
< ■ G'R 



\ZB3 

SNTED HY 






ELEMENTS 

12- H 
CHEMISTRY; 

CONTAINING THE 

PRINCIPLES. OF THE SCIENCE, 



EXPERIMENTAL AND THEORETICAL. 



INTENDED AS A TEXT-BOOK FOR ACADEMIES, HIGH SCHOOLS* 
AND COLLEGES. 



ILLUSTRATED WITH NUMEROUS ENGRAVINGS- 



BY ALONZO GRAY, A.M. 

PROFESSOR C? CHEMISTRY, NATURAL PHILOSOPHY, AND NATURAL HISTORY IN THB 
BROOKLYN FEMALE ACADEMY, NEW YORK. 



, 



FORTIETH EDITION, NEWLY REVISED, AND GREATLY ENLARGED. 



NEW YORK: 

PUBLISHED BY NEWMAN AND IVISON, 
178 Eulton Street, 

CINCINNATI : MOORJG & ANDERSON. AUBURN : J. C. IVISON & CO. 
CHICAGO: S. C. GRIGGS & CO. 

13.18, 









■ntkred, according to Act of Congress, in the year 1848, by 

ALONZO GRAY, 

In the Clerk's Office of the District Court of the United States for ttw 
Southern District of New York. 



fttA!amlnTii9ka 

/rrt' 86,1*31 



THOMAS B. SMITH, STEREOTYPER, J. D. BEDFORD. PRINTER, 

316 WILLIAM STREET, M V, 138 FULTON STREET 



5*. 



PREFACE 



In compiling the first edition of this work, the author 
attempted to prepare a text-book which should be well 
fitted for elementary instruction. Most of the works on 
chemistry appeared to him to be either too profound, on the 
one hand, for those who were just commencing the study, or 
too superficial, on the other, for those who wished to obtain 
a scientific knowledge of the subject. 

The design was to avoid these two extremes, and com- 
bine the scientific with the popular and useful parts of the 
subject. The rapid sale of the first edition, and its intro- 
duction into several colleges, have led to the inference that 
the attempt has not been wholly unsuccessful. The author 
has therefore been induced to revise and enlarge the work, 
and put it into a permanent form. A large amount of 
matter, and numerous engravings, have been added, for the 
purpose of rendering the work better adapted to academies 
and other schools. 

It is believed that greater success would attend the efforts 
of teachers in this branch of science, if more attention were 
given to the principles of chemistry, and less to its details. 
The fundamental principles being thoroughly understood by 
the student, he is prepared to attend to the details with 
greater pleasure and success, as he will be able to connect 
the effects with their appropriate causes. 

Under the influence of this belief, the author has given a 
greater prominence to the imponderable agents and the thir- 



4 PREFACE. 

teen non-metallic substances, than to other parts cf the work 
Most of the illustrations and experiments are introduced m 
this part, so as to present and illustrate the philosophy oi 
chemical combinations, and the general nature of the com- 
pounds thus formed ; in other words, the causes of chemical 
changes and the mode of studying them. 

By the introduction of numerous experiments and illus- 
trations, the object has been to give to the work a prac- 
tical character, so that the teacher, with a very simple 
apparatus, and with limited means, may be able to give 
numerous experimental illustrations to his classes. The im- 
portance of studying chemistry experimentally, is admitted 
by all ; and to aid teachers in constructing the more simple 
forms of apparatus, many notes and drawings have been 
added, and experiments described, which may easily be 
performed by those who are not privileged with more costly 
and extensive means of illustration. 

In the arrangement of the imponderable agents, the phe- 
nomena of common and voltaic electricity, electro-magnet- 
ism, and magneto-electricity, are classed as effects of one 
agent — electricity. 

In the arrangement of the simple substances, the logical 
order has been adopted ; that is, each simple substance is 
described, and then its combinations with those only which 
have been previously described ; so that only one substance 
with which the pupil is unacquainted is presented at a time. 
This classification appears to be the most convenient for 
presenting the different compounds, and less liable than any 
other to confuse the mind of the learner. This order, how- 
ever, has been adopted only with the simple substances and 
their binary compounds. 

The salts occupy a separate chapter, in the arrangement 
of which Turner's Chemistry has been made the basis 
Several new salts, and one entire family, — the silicates, — 
oave been added* 



PREFACE , 



The chapter on Organic Chemistry has been entirely re- 
written, and the whole very much enlarged, exhibiting the 
new views contained in the works of Kane, Graham, and 
Pownes — to which works, for further details, the student is 
referred. 

The chapter on Analytical Chemistry has been consider- 
ably enlarged ; but the methods of analysis have became so 
accurate, the details so minute, and the processes so com- 
plicated, that those who would obtain a full mastery of the 
subject, must consult works which treat particularly cf 
chemical analysis. Sufficient only has been inserted to 
give the pupil some idea of the nature of the processes, and 
to enable him to test, if not actually to analyze, the sub- 
stances which are mentioned. 

The Glossary of chemical terms has been selected from 
that prepared by Daniel!, of London, and adapted to this 
work. The table of contents has been much enlarged, and 
a complete analysis of the work presented, in the form cf 
topics, which are" intended to be used instead of questions ; 
the topics being so arranged that, when the teacher sug- 
gests one, the pupil may give a complete description of it. 
This plan, it is believed, will prevent the evils incident to 
direct questions, while it will secure ail their advantages. 

Chemical formulae have been extensively adopted. This 
appears highly important, especially for those who intend 
to become thorough students in the science. The notation, 
(the use of symbolical language,) to express, in a condensed 
form, complicated chemical changes, seems to hi as useful 
in chemistry as in algebra, and, although these symbols may 
be unintelligible to the common reader, he who will thorough- 
ly study them will find them the most efficient aid to a clear, 
definite, and easy comprehension of the whole science. 

In the description of the ponderable bodies, brevity has 



6 MtEFACE. 

been consulted, as far as was consistent with perspicuity 
The illustrations and descriptions are much more extendea 
in the first two hundred pages than in other parts of the 
work. The method of description which is employed in 
natural history has been adopted, where the subject did 
not require a more popular style. By this means, ana by 
using different kinds of type, a large amount of matter nas 
been condensed into a small compass, while, at the same 
time, that which is more important to be studied is rendered 
conspicuous. Many subjects of minor importance are only 
alluded to, and reference frequently made to more extensive 
works. 

The sources from which most of the materials have been 
drawn, are the works of Turner, Graham, Kane, and 
Fownes. Other works have been consulted, and also many 
original papers in the scientific journals of the day ; and it 
is confidently believed, that in the recent revision of the 
work no. important discovery has been omitted. 

A, G. 

Brooklyn Seminary, 
January, 1848. 



CONTENTS 



INTRODUCTION. 

Pa* 

Science defined — Physical and Natural science 21 

Definition of matter — how many properties does it embrace ?..... 21 

Division of Natural Science. 

I Natural Philosophy — method and object of. 21 

II. Chemistry — method and object of. 22 

III. Natural History — method and object of. 22 

Plan of the Work. 

Part I. Imponderable Agents — why so called 22 

II. Chemical Affinity — definition of. 23 

III. Ponderable Bodies — chemical and natural substances. 24 

Division of substances ; simple and compound bodies. . . . 24 
Analysis and synthesis; arrangement of chem. substances 24 

PART FIRST. 
IBXPO^TDERABLE AGENTS. 

CHAPTER I. — CALORIC. 

The term heat how used — meaning of caloric 25 

1 Sensible caloric defined. — 2. Insensible caloric do 25 

Sect. 1. Sensible Caloric — Communication of. 

The most important property of sensible caloric 26 

I. Conduction — meaning and illustration of. 26 

Conducting power ; how does it differ in bodies ? 26 

Different degrees of this power illustrated 27 

1. Conducting power of solids ; illustrated by conductometer 27 

Best and poorest conductors, metals, stones 27 

Uses of conductors, benevolence of God illustrated 28 

Ratio of the conducting power of solids 28 

2. Conducting power of liquids ; how are liquids heated ? Ills 28 

Heat applied at the top of liquids in a glass jar 29 

3. Conducting power of gases ; how are they heated ? 29 

II. Radiation — defined; radiant caloric, how projected ? 30 

1. Law of the intensity of heat at different distances 30 

2. Degree of radiation, dependent upon what ? 30 

Difference between bright, and dark or rough surfaces, Ills 30 

Greater radiating power of rough surfaces, depends on what ? . • 30 



8 CONTENTS. 

3. Rapidity of radiation dependent upon what ? 31 

III. Disposition of Radiant Caloric — reflect., absorb., transmit. 31 

1. Reflection of caloric ; law of reflection, angles of incidence and 

reflection. Concave mirrors described 31 

2. Absorption of caloric ; depends upon what ? .*. . 32 

Best absorbers, reflectors, and radiators „ 32 

Color of surface ; its effect upon the power of absorp,, Ills 32 

3. Transmission of caloric ; through air and gases, glass, etc.. 32 

Opinions of Leslie, Brewster, De la R,oche, and other chemists. 33 

Radiant caloric modified by its connection with solar light 33 

IV. Theories of Radiation — how many are worthy of notice ?. . 33 

1 . Theory of Pictet, described 33 

2. Theory of Prevost, do. grounds of preference 33 

V. Application of the Theory of Prevost to the Expl. ofvari's Phen 

1. The phen. of the mirrors explained ; apparent radiation of cold. . 34 

2. Formation of dew, process described and explained 34 

Quantity of dew ; dep. upon what? grass, and polished surface. . 34 
Why is there no dew in a cloudy night ? 35 

VI. Cooling of Bodies — different modes by which it is effected. 35 
Velocity of cooling, defined ; law of cooling, according to Newton. 35 

VII. Prac. Application of the Laics of Conduct, and Radiant Caloric. 

Best materials for windows ; double walls, doors, windows 35 

Object of clothing ', kind best for different seasons of the year 36 

Effects of Free Caloric. 

I. General Lavj — Caloric expands all Bodies; Liquids, Solids, Gases. 
1*. Caloric expands solids : illustrated by what ? 36 

2. Equal degrees of caloric expand some solids more than others. . . 36 
Illustrated by pyrometer ; description of pyrometer 36 

3. Effect of equal add'ns of caloric on the same solid at dif. temp's. 37 
Expansion of brass and iron rods in the higher or lower temp's. . 37 

4. Uniformity in the expansion of certain solids 37 

II. ' Caloric expands Liquids more than Solids. 

1. Illustrated by heating water in a glass tube, common thermom'r 38 

2. Effect upon different liquids of equal degrees of caloric 38 

3. Effect upon the same liquids of equal degrees at different temp's 38 
Apparent exceptions to the general law that heat expands 38 

III. Caloric expands Gases more than Solids or Liquids. 

1. The expansion of air ; in glass ball, bladder 38 

2 Law of the expansion of gases at all temperatures 39 

Difference between gases, and solids or liquids 39 

Theory of expansion ; caloric and cohesion, how related ? 39 

IV. Apparent Exceptions to the General Law. 

Water near the point of congelation ; Illustration 40 

V. Force of Expansion ichen Water freezes. 

Florentine Academicians ; experiments of Major Williams 40 

Theory, or the cause of expansion when water freezes 40 

VI. Advantages of this Excep. — wisdom and benevolen. of God 40 
Process of freezing water; effect if the contractions continued..-.. 41 
Cast iron and antimony, how affected in cooling ? 41 

VII. Practical Uses of the General Laio of Expansion and Contract. 

Banding of wheels, steam-engine boilers, gallery at Paris 41 

Winds ; depend upon what ? land and sea breezes 42 

Thermometers ; by whom invented ? , 42 

Air thermometers ; plan of Sanctorius, illustrated 42 



CON I I 



9 



Objections to air for the common purposes of a thermometer. ... 43 

2. Differential thermometer of Leslie ; mode of construction 43 

Best substance for thermometers ; solids, liquids, or gases ? 43 

3. Mercurial thermometer ; construction and graduation. ....... .. 44 

Different scales; Fahrenheit's, Reaumur's, De Lisle 's, Celsius's <o 

4. Register thermometer; construction, object, and principle- 5 of. . . 45 
Pyrometers ; derivation and meaning of the term 46 

1. Pyrometer of Wedgwood ; founded upon what property 40 

2. do. of Daniell ; construction of * 4G 

'3. Metallic thermometer of Brequet ; construction, Illustrated 46 

Amount of knowledge obtained by therm's and other instruments 47 



Sect. 2. Insensible Caloric. 

Specific caloric ; meaning of, illustrated 47 

Methods of determining specific heat of solids and liquids 48 

Laics of Specific Heat, 1,2,3.4,5 48 

Practical inference from the doctrine of specific heat 49 

Effects of Insensible Caloric. 

I. Liquefaction — states in which bodies exist 49 

1. Point of liquefaction ; fusion, congelation 49 

2. Caloric of fluidity ; Illustr., quantity in different substances.. .. 49 

3. Freezing mixtures ; how produced ? salt and snow. 50 

4. Limit to the degree of cold ; greatest cold by these processes. . . 51 

5. Absolute amount of heat ; estimated by what means ? 52 

II. Vaporization — defined, difference between gas and vapor. .. 52 

Definition of volatile and fixed bodies ; liquids how vaporized 52 

Ebullition ; 1. Boiling point defined * is it fixed ? 52 

2. Circumstances* which modify the boiling point of liquids 53 

Pressure of the atmosphere ; variations of 53 

Barometer, construction and illustration of. 53 

1. Law of the boiling point as the pressure diminishes 53 

Mercury frozen under the exhausted receiver of an air-pump . . 53 

2. Lav/ of the boiling point as the pressure increases 54 

Marcet's digester; construction of 55 

Absorption of free caloric in ebullition, Illustration £5 

Table of the latent heat of different vapors 56 

Steam : its formation and laws of expansive force 56 

Sensible and insensible caloric of steam at all temperatures. . ... 57 

Application of Steam to practical Purposes. 

1 . Warming rooms ; water baths, dyeing vats. etc.. 57 

2. Steam engine ; invention of, principle illustrated 58 

3. Steam generator of Mr. Perkins ; steam artillery 58 

Distillation; process illustrated and described 59 

Evaporation — difference between it and ebullition 59 

1. Evaporation of different liquids ; depends upon what ? 59 

2. Effect of increased and diminished pressure upon evaporation. . . 59 

3. Extent of surface ; how does it affect the rapidity of evaporation GO 

4. State of the atmosphere ; li ' " " " bU 

sorption of free Caloric by Evaporation ; cryophorus described 60 

6. Cause of evaporation ; how have some accounted for it? 61 

7. Uses of evaporation ; cooling rooms, warm climates. 61 

Effect of perspiration explained ; fire kings, oven girls 61 

Injurious effects of evaporation, miasma, fever and ague G$ 

1* 



10 



CONTENTS. 



Hygrometers , reduced to three principles 62 

1 . Saussure's hygrometer ; depends upon what property ? 62 

2. Leslie's hygrometer ; depends upon what property ? 62 

3. Hygrometer Daniell's dew point, how determined . . 62 

Application of the Laws of Insensible Caloric to the Expl. Nat. Plien. 

1. Processes of thawing and freezing ; effect upon climate 63 

2. Effect of vaporization ; to modify the heat of summer 64. 

3. Effect of condensing vapors ; rain, source of the cold 61 

4. Effect of freezing water; to modify the approach of winter 64 

Why are the shores of a country warmer in winter, etc.. ...... 64 

Sect. 3. Sources or Caloric and or Cold. 

1. Sun ; concentration of its rays, degree of heat 65 

2. Chemical action ; combustion defined . 65 

3. Condensation ; machinery, friction, percussion 65 

4. Vital action ; how is caloric produced in animals ? 66 

Sources of cold, what ? 66 

Sect. 4. Nature of Caloric 

Theory of Sir W. Herschel and Prof. Airy; undulatory theory.... 66 
Theory of Newton ; what supposition did he make ? , 66 

CHAPTER II. — LIGHT. 

I. Physical Properties of Light — belong to what science ? 67 

Velocity of light ; disposition of it 67 

II. Refection — the circumstances which govern it. 67 

III. Refraction — defined, refrangibility, Illustration 67 

IV. Decomposition of Light — how many kinds of rays ? 68 

1. Colorific rays; mode of separating them by prism, Illustration.. 68 
Opinion of Wollaston, of Brewster, illuminating power 69 

2. Calorific rays; their position, and degree of refrangibility 6:3 

3. Chemical rays ; their position in the spectrum 69 

1. Photographic drawing, Ills. 2. Daguerreotype described .. . 61) 
Magnetic rays ; do they exist ? 70 

V. Absorption — denned 70 

1. Effect of different surfaces to absorb different colors 70 

Why are objects colored? what produces the variety ? 70 

2. Effect of chemical constitution upon the power of absorption. .. 70 

3. Effect of absorbing all the rays 70 

VI. Ignition and Incandescence — artificial light, of oil, lime 71 

VII. Phosphorescence — defined 71 

1. Solar phosphori ; substances affected by the solar rays 71 

2. Phosphorescence from moderate heat ; lime 71 

3. Animal and vegetable phosphori 72 

VIII. Photometers — object and description of ""2 

Photometer of Leslie, of Count Rumford 72 

Sources of light ; similar to those of caloric 72 

IX. Nature of Light — Newton's theory, undulatory theory 72 

CHAPTER III. — ELECTRICITY. 

Electricity ; mode of producing it 73 

Meaning of electrically excited, electrified, cause of it 73 



CONTENTS. H 



Sect. 1. CoimoN Electricity. 

1 Mode of exciting it ; frbtion upon resinous bodies 74 

2. Friction upon vitreous substances ; effects of. 74 

3. Bodies electrified with each kind ; how affected ? 74 

Theories — 1. Theory of Franklin ; positive and negative states. ... 74 
2. Theory of Du Fay ; vitreous and resinous, correspond to what ? 74 

Inference from the last theory ; law of each fluid 75 

Existence of the two fluids shown ; gold leaf electrometer 75 

Non-conductors ; defined, conductors, do., insulators 75 

Electrical machine described; Ills., direction of currents 76 

Induction — defined and illustrated, several conductors 76 

Theory of Induction — attraction and repulsion accounted for 77 

Application of the Theory. 

1. To the spark. 2. Stroke of lightning. 3. Leyden jar 77 

4. Electrophorus ; described, illustrated, its use 78 

Electrometers or Electroscopes — object of 78 

Balance electrometer ; described, uses of 79 

Laws of the Accumulation of the Electric Fluid. 

} . Quantity of electricity on a conductor ; depends on what? 79 

2. Mode of distribution ; on a sphere, ellipsoid, effect of points. ... 79 

3. Tendency to escape from points due to what property ? 79 

4. Law of attraction and repulsion between two electrified bodies.. 79 

Sect. 2. Voltaic Electricity, or Galvanism. 

History — discovery of Galvani,liis theory 79 

Diseovery of Volta; identity of galvanism, magnetism, etc 80 

1. Simple Voltaic Circles — description of. 80 

Direction of the positive current; closed and broken circuit 80 

Different modes of forming voltaic circles 81 

Chemical action necessary to excite currents ; form of battery 81 

Calorimotor ; why so calied ? 81 

li. Compound Voltaic Circles — 1. Voltaic pile, described 8i 

2. Best form of the galvanic battery described 82 

Size and number of plates; Hare's deflagrator other batteries.. .83,84 
Direction of the currents, relation of electricity to chem. affinity 84 

Tlieorics of Galvanism. 

I. Theory of Volta. 2. Of Wollaston. 3. Of Davy 85 

Laws of the Action of Voltaic Circles. 

Difference between quantity and intensity 86 

1 . Relation between the exciting liquid and the zinc 86 

2 Tension and quantity of electricity in simple circles 86 

3 Mode of measuring the energy of voltaic currents 86 

Decomposing power; power of deflecting magnetic needle.... 87 

4. Velocity of electricity through perfect conductors 87 

Effects of Voltaic Electricity or Galvanism. 

I. Comparison of Common and Voltaic Electricity. 

1. Action of voltaic electricity upon the gold leaf electrometer. . . . 87 

2 Leyden jar charged by the battery ; conditions of 87 

3. Velocity of common and voltaic electricity ; effects of. , 87 

4. Tension of voltaic electricity; striking distance 33 

5. Effect of voltaic electricity upon the animal system 8tj 

G. Deflection of magnetic needle and chemical decomposition • . . • gg 



12 CONTENTS. 

II. Power of Voltaic Currents to ignite the Metals — Illustration SH 
Theory ; heating- power of calorimolor, and compound battery. . . . 88 

III. Chemical Effects of Galvanism — history 80 

1. First substance decomposed ; Illustration . 89 

Difference between substances as ascertained by galvanism. .. 90 

2. Transfer of chemical substances ; Illustration 90 

Theory of Faraday,, of Davy ; electrodes, anode and cathode ... 91 

Electroiyzed, electrolyte, ions, anions, and cations 9L 

Results of Faraday's Investigations. 

1. Decomposition by primary and secondary action 92 

2. Compounds which are electrolytes 92 

3. Simple substances form ions 92 

4. Single ions indifferent to voltaic currents 92 

5. Conditions for the decomposition of water 92 

6. Substances which form electrodes 92 

7. Conditions necessary to electro-chemical decomposition. ...... 92 

8. Conduction of electric currents in cells of battery 93 

9. Electro-chemical equivalents ; defined 93 

Faraday's theory of electro-chemical decomposition 93 

Magnetic Effects- of Electricity or Electro-Magnetism. 

History ; discovery of Oersted 04 

I. Influence of Voltaic Currents upon the Magnetic Needle. 

1, 2, 3, 4, 5. Position of the needle in reference to voltaic currents 94 

6. Plane in which a needle moves as related to voltaic currents. . . 95 

7. Electro-dynamic action results from what ? 95 

Galvanometers or Multipliers ; Illustration 95 

Revolving* Rectangle ; described 93 

II. Influence of Voltaic Currents upon soft Iron and Steel. 

1 . Helix and stand ; description of. 97 

2. Kind of pole ; dependent upon what ? Illustration 98 

3. Electro magnet '; what weight will it sustain ? 98 

4. Magic circle ; description and illustration of 93 

5. Vibrating magic circle ; description and illustration of 99 

III. Volta- Electric Induction — Separable Helices, described... 101 

IV. Magneto- Electric Induction — defined; illustration 105 

Magneto-Electric Machine described 105 

V Theory of Electro-Magnetism and Magneto- Electricity 106 

Application of the theory ; magnetism of the earth ,....«,. 103 

VI. Tkermo-Electricity — defined; Illustration 103 

VII. Nature of Electricity. 

VIII. Use of Electricity — 1 . Medicinal Effects 1 08 

2.. Application to the propelling of Machinery 1 09 

3. Electro-Magnetic Telegraph ; principle and description 109 

4. Electrography ; Electrotype, description of, theory 1 12 



PART SECOND. 

Cause cf chemical changes ; affinity defined I 13 

Varieties of Chemical Affinity. 

Simple affinity, defined, elective affinity, double elective affinity ... 114 



CONTENTS. 13 

Circumstances which modify Affinity. 

I. Cohesion — opposes chemical action, how destroyed ?....,.« 115 

1. By pulverization ; Illustration .• • « • 115 

2. By solution ; solvents ; saturated solution U(> 

Insolubility ; its effect on affinity ; Illustration 116 

3. Fusion, defined, effect 117 

II. Elasticity — its effect on affinity 117 

1. Influence on decomposition , 117 

2. Effect of a high temperature upon gaseous mixtures 117 

III. Quantity of Mattel' — its effect upon affinity 117 

IV. Gravity — specific gravity, effect 118 

V. Imponderable Agents — effect of, upon affinity 118 

Measure of affinity ; how is the force determined ? Illustration .... 119 
Effects of Affinity. 

I. Change of Chemical Properties — Illustration 120 

II. Change of Color — Illustration ; dropping tube. 120 

III. Change of Form — Illustration of 121 

IV. Change of Temperature — Illustration . . , 121 

V. Change of Specific Gravity — Illustration 1 21 

Laws of Chemical Affinity. 

I. Indefinite Proportions — defined ;- how many cases ? ....... . 122 

II. Definite Proportions by Weight — described 122 

1st law ; mode of expressing the ratio of combination 123 

Standard of comparison ; equivalent, meaning of 123 

Apparent variations of law ; Illustration 123 

2nd law ; constitution of each substance fixed 124 

Discovery of these laws, by whom, their use 124 

III. Definite Proportions by Volume. 

Compared with those by weight 123 

Atomic Theory ; existence of atoms 12b 

Theory of definite proportions by weight ; Illustrated 126 

Atomic weight ; absolute weight, magnitude and form of atoms. .. 126 

Isomerism, defined, reconciled with definite proportions 127 

Cause of chemical affinity } electricity, second causes 1£7 



FAST TH1RI3, 



Specific gravity ; defined ; standard of comparison „,.«,. J 29 

1. Method of obtaining specific gravity of solids 129 

2. do of liquids ; aerometer, Illustration. 3. Of gases 130 

.Nomenclature — description of, history of, uses 1 30 

1. Method of naming simple substances ; table of 1 31 

2. Acid compounds receive what terminations, prefixes? etc 131 

3. Binary compounds not acid ; prefixes and suffixes. 132 

Metals and alloys ; hydrates 133 

4. Ternary compounds or salts ; terminations, etc 133 

Notation, defined, symbols described, their use 134 

Table of the symbols and equivalents of the thirteen non-metallic 

elements, and the symbols of their compounds with each other 135 



14 CONTENDS 



CHAPTER I. — CHEMICAL SUBSTANCES. 

Class I. Non-Metallic Elements and their Primary 
Compounds. 

Sect. 1. Oxygen. 

History of discovery ; natural history, process 136 

Pneumatic cistern, description of, gasometers 13? 

Theory of process by manganese ; by chlorate of potassa 138 

Physical and chemical properties ; Illustrated 139 

Effects of combustion ; theory 140 

Oxigenation and oxidation ; relation of oxygen to animals 141 

Sect. 2. Chlorine. 

Symb. Equiv. Sp. gr. ; history of discovery 141 

Natural history ; 1. Process, theory. 2. Process, theory 142 

Physical and chemical properties ; Illustrated 143 

Relations to water, to hydrogen ; bleaching effects 144 

Relations to animals ; uses ; 1. Bleaching process, theory 144 

2. Disinfecting agency ; dissecting rooms ; diseases of skin 145 

Hypochlorous acid ; Symb. Equiv. Sp. gr. process, properties . . 146 

Chlorous, chloric, and perchloric acids ; process, properties 147 

Sect. 3. Iodine. 

Symb. Equiv. Sp.gr.; history of discovery ; natural history .... 148 

Process ; Physical and chemical properties, tests, uses 149 

Iodic acid ; process, properties ; periodic, and chloriodic acids. .... 150 

Sect. 4. Bromine. 

Symb. Equiv. Sp. gr. ; history of discovery 151 

Natural history ; process, physical and chem. properties illustrated 152 

Bromic acid ; properties, chloride of bromine; bromide of iodine .. . 153 

Sect. 5. Fluorine. 

Symb. Equiv. ; natural history, properties as far as known 153 

Sect. 6. Hydrogen. 

Symb. Equiv. Sp.gr.; history; nat. history, processes 154 

1. By heated iron ; Illustration 155 

2. By zinc and acidulated water ; theory, impurities. 155 

Physical properties; soap bubbles, method of filling gas bags.. 156 

Aerostation ; description of balloons 157 

Chemical properties ; illustrated, theory, relations to animals.. 157 

Protoxide of hydrogen, water ; Symb. Equiv. Sp. gr., process.. .. 158 

Physical and chem. properties illustrated, solvent properties 159 

Composition, eudiometer described; compound blowpipe 160 

Heat produced by blowpipe ; binoxide of hydrogen, properties .... 161 

Hydrochloric acid ; history, natural history, process, theory 162 

Woulfe's Appa., physical and chemical properties, illustrated .... 163 

Constitution ; uses and impurities 163 

Hydriodic acid ; Symb. Eq. Sp.gr.; process, properties, tests. .. . 164 

Hydrobromic acid; Symb. Equiv. Sp. gr. ; properties 165 

Hydrofluoric acid; history, process, theory, uses illustrated 165 



CONTENTS. 15 

Sect. 7. Nitrogen. 

Symb. Equiv. Sp. gr. history of discovery 166 

Natural history; process, 1. By phosphorus 167 

2. By sulphur and iron. 3. By muscle and nitric acid 167 

Theory of process ; physical and chemical properties 167 

Effect on combustion ; respiration, its nature 167 

Common air; physical properties, elasticity illustrated 168 

Pressure of the air ; how discovered ? 168 

Extent and composition of the atmosphere 169 

Theory of the diffusion of gases of different sp. gr. ; Illustrated. 170 

Impurities of the air ; eudiometry, uses of the air 171 

Protoxide of nitrogen; history, process, theory of, properties 171 

Respiration of; effect upon animals 172 

Binoxide of nitrogen; history of discovery, process 172 

Theory of process, properties, illustrated, affinity for water 173 

Hyponitrous acid ; properties, nitrous acid, history 173 

Processes, properties, respiration of. JYitric acid, history 174 

Process, illustrated, impurities, properties 175 

Chemical properties, illustrated, uses 176 

JVitrohydrochloric acid, aqua regia ; nitrohydrofluoric acid 176 

Quadrochlorids of nitrogen ; process, properties 377 

Tcriodide of nitrogen ; Symb. Equiv. properties 177 

Ammonia; history, process, theory of, properties, tests, uses 178 

Sect. 8. Carbon. 

Symb. Equiv. Sp. gr. ; nat. hist.; the diamond, where found, uses jgo 

Plumbago, anthracite, bituminous coal, peat, and lamp-black jg^ 

Charcoal ; 1. Process by slow combination of wood igi 

2. By distillation of wood. 3. By hot sand Ig2 

Properties, hardness, theory of its absorbing properties Ig2 

Clarifying agency, combustion of, durability of, infusibility, uses jg3 

Carbonic oxide ; carbonic acid, history of discovery jg3 

Nat. hist, process, theory of, relation to flame, to water. jg5 

Fermenting liquors, best test of carbonic acid, solidification of . . . . jgg 

Relations to animals, choke-damp jg7 

Sources of carbonic acid, respiration explained 2gg 

| Chloride, -per chloride of carbon, Chloro- carbonic acid, chloral. . . . jgg 

Periodide and protiodide of, bromide of carbon, properties Ig9 

Dicarburet of hydrogen ; history, process, properties, Illustration.. 190 

Olefiant gas, or 2 carburet of hydrogen, Symb. Equiv. Sp. gr.. . . . 190 

History, process, theory of, properties, Ills. ; action of chlorine. . . . 191 

& Carburet of H. etherine, £ carburet, parrijjine, eupione, naphtha.. 192 

jVaphthaline, paranapthaline, idrialine, camphene, and citrene 192 

Gas lights ; history, process, portable gas, fire-damp 193 

Efforts of Davy ; discovery of Wollaston 195 

Effect of gauze wire upon flame ; safety lamp, construction, etc. . . 195 

Bicarburet of nitrogen or cyanogen, history, process, properties. . . 196 

Cyanic, fulminic, and cyanuric acids 196 

Paracyanuric acid, chloride, bichloride, and bromide of cyanogen.. . 197 

Hydrocyanic acid. Process, properties 197 

Sect. 9. Sulphur. 

Symb. Equiv. Sp. gr. ; nat. hist., process ; Illus., sublimation. . , . . 198 

Properties, effect of heat, structure, impurities, uses 199 

Hypajsulphurous and sulphurous ordds^ process, theory, crucibles. 200 



16 CONTENT*. 



■! 



Hyposulphuric acid, process, properties ; sulphuric acid, process 

Hydrous sulphuric acid, manufacture of, theory 20i3 

Properties, affinity for water ; Ilkis. decomposition, tests 203 

Uses ; dichloride, iodide, and bromide of sulphur 203 

Hydro sulphuric acid, process, theory of 205 

Properties, liquid form, tests, uses ; Illustration 20 J 

Production of sulphur; Illustration; hydrosuLphurous acid 207 

Bisulphuret of carbon, or alcohol of sidphur, carbosulphuric acid.. 207 

Sulphuret and bisulphuret of cyanogen 208 

Hydrosulphocyanic and cyanohydrosulphuric acids ?f)$ 

Sect. 10. Phosfhorus. 

Symb. Equiv. Sp. gr. ; history, source 203 

Process, properties, inflammability ; Illustrated 200 

Theory of the heat and light, relation to animals 210 

Oxide of phosphorus ; hypophosphorous acid 210 

Phosphorous acid, process ; phosphoric acids 2il 

Phosphoric acid, process, properties ; pyro and meia phosp. acids. . 21 1 

Sesquichl oride of phosphorus, Symb. Equiv., process, properties. . 212 

Perchloride, protiodide, sesquiodide, and periodJ.de of phosphorus. . 213 

Protobroinide, perbromide, phosphurct of hydrogen, properties 213 

Perphosphuret of hydrogen, process, properties, inflammability of, 213 

Jack o' the lantsrn ; sulphuret of phosphorus 214 

Sect. 11. Boron. 

Discovery ; process, property 215 

Boracic acid; source, process, evaporating dishes 21(1 

Terchloriue of boron ; fluoboric acid, suphuret of boron 217 

Sect. 12. Selenium. 

Discovery, o?cide of, selenious acid, properties 217 

Selenic acid ; chloride and bromide of, hydrosclenic acid 218 

Sect. 13. Silicon. 

Symb. Eq., discovery, properties, silicic acid, nat. history, process, 2"20 

Chloride, bromide, and sidpihurtt of silicon, fluosUicic acid 221 



CHAPTER 11. 

Class II. Metals, with their Binary Compounds, 

General properties of metals, metallic lustre 223 

Sp. gr. of; malleability defined §2-2 

1. Ductility, tenacity. 2. Hardness. 3. Structure. 4. Fusibility 223 

5. Volatility. 6. Affinity for other simple bodies 333 

Combustibility ; number and date of discovery 2 i 

Classification of the metals. 227, 228 

Order I. Metals ivliick, by Oxidation, yield Jilkalies or Earth 
Sect. 1. Metallic Bases of the Alkalies. 

Potassium; history of discovery c <#8 

Process, properties, combustibility ; Illustration 220 

Protoxide of potassium ; properties, hydrate of; Ills., tests 230 

Potassa ; teroxide, iodide, bromide, fluoride, and chloride of. 230 

Hyduret, nituret, sulphurets, phesphurets and seleniurct of. . .. .- 231 



CONTENTS. 17 

Cyanuret, properties ; sulphocyanuret of 233 

Sodium; Symb. Equiv. Sp. gr 232 

Process, properties, affinity for oxygen, 233 

Protoxide of soda, process ; sesquioxide, chloride of, origin, uses. 234 

Iodide, bromide, fluoride, sulphuret, and cyanuret of 235 

Chloride of soda, alloys of sodium and potassium 235 

Lithium; protoxide of, or lithia, process, properties, fluoride of . . . . 236 

Sect. 2. Metallic Bases or the Alkaline Earths. 

Barium ; protoxide of, or baryta, how distinguished 237 

Binoxide, chloride, iodide, bromide, fluoride, sulphuret 238 

Cyanuret, sulphocyanuret, phosphuret of 239 

Strontium ; protoxide, strontia, peroxide and chloride of. 239 

Iodide of, fluoride, protosulphuret 240 

Calcium ; protoxide of, or lime, peroxide, chloride, uses; iodide.. 240 

Bromide, fluoride, bisulphuret, phosphuret of, chloride of lime .... 241 

Magnesium ; discovery, process, properties 242 

Protoxide of, or magnesia, properties, uses 043 

Chloride of, iodide, bromide, fluoride 243 

Sect. 3. Metallic Bases of the Earths. 

Aluminium; discovery, process, properties, sesquioxide of 244 

Sesquichloride, sesquisulphuret, sesqutphosphuret 245 

Glucinium ; Symb. Equiv. Sp. gr. ; discovery, properties 246 

Sesquioxide of, glucina, discoveiy, process, properties 246 

Yttrium ; Symb. Equiv. ; process, properties 246 

Thorium ; Symb. Equiv. ; process, properties, protoxide, do 247 

Zirconium; Symb. Equiv. ; discovery, process, properties 247 

Order II> Metals the Oxides of which are neither Alkalies nor 

Earths. 
Sect. 1. Metals which decompose Water at a red Heat. 

Jdanganese; history, process, properties, protoxide of, properties.. 248 

Sesquioxide, peroxide, red oxide, varvicite, manganic acid 249 

Perchloride, perfluoride, protosulphuret, and cyanuret, alloys 250 

Iron; Symb. Eq. Sp. gr. : history, nat. history, process, properties 251 

Protoxide of; process, properties, uses, 252 

Peroxide of; process, properties, etc. ; black oxide, source, tests.. 253 

Protochloride ; perchloride, protiodide, properties 253 

Periodide, protobromide, perfluoride, protosulphuret 254 

Sesquisulphuret, magnetic iron pyrites, tetrasulphuret 254 

Diphosphuret, perphosphuret, carburets, graphite, cast iron, steel. 255 

Protocyanuret, protosulphocyanuret, sesquisulphocyanuret 255 

Vine; Symb. Eq. Sp. gr.; history, nat. history /process, properties. 255 
Protoxide, hydrated oxide, chloride, iodide, bromide, fluoride, etc 257 
Cadmium ; oxide, chloride, iodide, sulphuret, and phosphuret of 257,258 

Tin; process, properties, stream tin, tin foil, protoxide of tin 259 

Besqui and binoxide, proto and bichloride, proto and biniodide of. . 259 
Protosulphuret, sesquisulphuret, bisulphuret, and tersulphuret of. 260 
Cobalt ; protoxide, zaffre-oxide, and peroxide of, sympathetic ink. 261 
Protosulphuret. sesquisulphuret, bisulphuret, and subphosphuretof 263 

Nickel ; properties, protoxide, sesquioxide, and chloride of. , 263 

Protosulphuret, disulphuret subphosphuret, and cyanuret of. .... . 264 



IS CONTENTS. 

Sect. 2. Metals which do not decompose Water at any Tem- 
perature, and the Oxides op which are not reduced to thb 
Metallic State by the sole Action op Heat. 

Arsenic, and its compounds 264 — 268 

Chromium and its compounds. Vanadium, ditto 268 — 270 

Molybdenum, compounds of. Tungsten, ditto. Columbium and An- 
timony 271— 273 

Antimony, compounds of. Uranium, Cerium, Bismuth. , ... 274 — 276 

Titanium, Tellurium. Copper and its compounds 277 — 289 

Lead and its compounds ; Galena, alloys, etc 281 — 282 

Sect. 3. Metals the Oxides op which are reduced to the Me- 
tallic State by a red Heat. 

Mercury and its compounds. Amalgams, Silver, ditto 283 — 287 

Gold, compounds of, alloys, water-gilding 288 — 290 

Platinum; palladium, rhodium, osmium, irridium 291 — 292 

CHAPTER III. 

Class III. — Salts or Secondary Compounds. 

Sect. 1. Crystallization. 

Crystal and crystalography defined , 293 

Planes, faces, edges, angles, primary and secondary forms of. 294 

I. Prisms have six-sided or four-sided bases 284 

(I.) Right Prisms. — 1. Hexahedron, or cube 294 

2. 3. Right square and right rectangular prisms 294 

4, 5. Right rhombic and right rhomboidal prisms 295 

6. Regular hexagonal prism 295 

(2.) Oblique Prisms. — 7: Rhombohedron. 8. Obi. rhombic prism . . 295 

9. Oblique rectangular prism. 10. Oblique rhomboidal prism 295 

II. Ociohedrons. — 11. Regular octohedron. 12. Square octohedron 295 
13. Rectangular oetohedrons. 14. Rhombic octohedrons 296 

III. Dodecahedrons. — 15. Rhombic dodecahedron 296 

Secondary forms ; cleavage defined, faces and direction of 296 

Isomorphism, crystallogenic attraction, water of crystallization 297 

Sect. 2. Oxy-Salts. 

General formula for the composition of the salts 302 

1. Sulphates — of potassa, soda, Glauber's salts . 303 

Of lithia, ammonia, baryta, strontia, lime, gypsum 304 

Of magnesia, alumina, manganese, protoxide of iron 305 

Of protoxide of zinc, (white vitriol,) nickel, cobalt, chromium 306 

Of copper, (blue vitriol.) mercury (turpeth mineral,) silver 307 

Nitro-sulphuric acid, sulphate of soda, lime, potassa and magnesia. 308 

Ammonia, soda, iron, chrome, andmangan, alums. 2. Sulphites. . .. 308 

3. Nitrates— ox potassa, (nitre beds,) of soda, ammonia „ , . 309 

Of baryta ; pyrotechny, green-fire 310 

Of strontia, (red-fire,) lime, magnesia, protoxide of copper 311 

Nitrate and dinitrate of protoxide of lead, of mercury, of silver 312 

Properties, illustration, lunar caustic, indelible ink 3l3 

4. Nitrites. 5. Chlorates — of potassa, properties . . . . < ul4 

Lucifer matches, chlorate of baryta, process, properties 3 15 



CONTENTS. 1 9 

6. Perchlorates. 7. Chlorites. 8. Hypochlorites. 9. Iodates 315 

Iodate of potassa. 10. Bromates. 11. Phosphates 316 

I. Phosphates — triphosph., diphosph., and phosphate of potassa.. 316 

Of soda and ammonia, ammonia, lime, magnesia, amm. and mag. 317 

Triphosphate of silver. — 2. Pyrophosphates 318 

III. Metaphosphates — of soda, baryta, silver, etc 319 

12. Arseniates ; of soda, table of compounds 319 

13. Arsenites ; general properties, tests 320 

14. Chromates ; of potassa, lead. 15. Borates; of soda, borax ... . 321 

16. Carbonates ; of potassa, soda, ammonia 322 

Of baryta, strontia, lime, magnesia • 323 

Of iron, copper, lead, white lead, mercury 324 

17. Double Carbonates 326 

18. Silicates; simple, bi, tri, and quadri silicates 327 

Sect. 3. Order II. Hydro-Salts; acids of 328 

Sect. 4. Order III. Sulphur-Salts; constitution of .... a. 330 

Sect. 5. Order IV. Haloid-Salts ; constitution and descrip. of. . 333 

CHAPTER IV.— ORGANIC CHEMISTRY. 

Organic and inorganic compounds compared 335 

Analysis of organic compounds 337 

Theory of compound radicals ; substitutes, etc 340, 341 

Theory of pyracids 342 

Sect. 1. Amylaceous Substances. 

Various kinds of starch 343 

Gluten, gums, Arabic, etc 344 

Lignin, xylodine 345 

Eremacausis, sugar, cane and grape 346, 349 

Saccharic acid, lactine, mucic acid 348 

Manna, saccharic, and vinous fermentation 349 

Acetous and viscous fermentation, theory of 350, 351 

Sect. 2. Compound Radicals. 

I. Alcohol, properties. Sulphuric ether 351, 352 

Hydrochloric, hydrobromic, hy driodic ether 353 

Mercaptan, nitric, hyponitrous and carbonic ethers 354 

Eoracic, silicic, oxalic, acetic, and formic ethers 355 

Oenanthic and benzoic ethers, sulphovinic and phosphovinic acids. . 356 

II. Aldehyde, acetous and acetic acids, vinegar 357 

Acetates of potassa, of ammonia, and of lead 358 

Acetates of copper, alumina, iron, zinc 359, 360 

III. Kakodyle — alkarsine, alkargene 360, 3(5 1 

Chloride, iodide, sulphuret, and cyanide of kakodyle 361 

IV. Products of the dry distillation of -wood: 

Methylic ether, wood-spirit, chloride of methyle 362 

Sulphate, nitrate, and oxalate, etc., of methyle 363, 364 

V. Formic Acid — formates of potassa, ammonia, etc 364 

Chloroform, bromoform. VI. Potato Oil, chloride of amyle 365 

VII. Valerianic Acid. VIII. Bitter Almond Oil 366 

Benzoic acid, chloride, iodide, etc., of benzoyle 367 

Bonzole, benzoine, benzile 368 

Amygdaline, amygdalic, and hippuric acids 368 



20 CONTENTS. 

IX. Salicene, hydro-salicylic, salicylic acids, chloride of. . . . . 369, 370 

X. Oil of Cinnamon, cinnamic acid 371 

XI. Oxide of Carbon, oxalic acid, oxalates, potassa, lime.. 371, 372 

XII. Cyanogen, cyanic and fulminic acids, cyanite of ainm. (urea) 373 

Cyanuric and hydrocyanic (prussic) acids , 379 

Sulphocyonide and cyonate of potassium 375 

Ferrocyonide of potassium, ditto of iron 376 

XIII. Mellone, hydromellonic acid, mellonide of potassium, etc... 277 
XIV. . Uric Acid, (lithic acid,) allontoin 378 

Alloxan, alloxantin, murexide, murexan 376 

Sect. 3. . Organic Acids, malic, citric, aconitic, tartaric 380 

Tartrates of potassa and soda, antimony and potassa, tannic acid. . . 381 

Acids, gallic, mellitic, lactic, uric, and croconic 382 

Comenic, succinnic, oleic, crenic, apocrenic 383 

Sect. 4. Vegetable Alkalies, morphia 384 

Narcotina^cinchonia, quinia 385 

Strychnia, emetia, nicotina, codeia, brucia, parilla. 386 

Sect. 5. Oils and Fats. Fixed oils, glycerine 387 

Stearine. stearic acid, margarine, margaric acid 388 

Oieine, oleic acid, palm-oil, palmetic acid, olive and croton oils 389 

Hogs lard, soaps, butter, butyrine, butyric and caporic acids . . 382, 390 

Wax. 2. Volatile oils, spirits of turpentine 391 

Camphor, resins, copal, lac, mastic, amber, balsams 392 

Gum Resins, aloes, chaoutchouc, creosote . . 393 

Sect. 6. Coloring Matters, lakes, blue dyes 394 

Indigo, isatine, isatinic acid, chlorisatine, etc 395 

Red Dyes, cochineal, archil, erythrilin, litmus, madder . . . v 396 

Yellow Dyes ; black dyes, logwood, Turkey reds 397 

Sect. 7. Nutricious Substances, fibrine 397 

Albumen, ligumine, proteine, gelatine, glycocoll 398, 399 

Sect. 8. Complex Animal Substances, hernatosin 399 

Blood, animal beat, theory of 401 , 402 

Saliva, gastric juice, bile, bilin, tannin : - 403 

Chyle, milk, lymph, mucus, pus, sweat, urine 404 

Urinary calculi, eggs, bones, teeth, shells 405 

Horns, hair, skin, wool, silk, brain and nerves 400 

Sect. 9. Growth and Nourishment of Plants and Animals 401 

Germination, growth of plants, food of plants, source of carbon 408, 409 

Humus, humic acid, etc., source of hydrogen 409 

Source of nitrogen, nourishment of animals 410 

Respiration, equilibrium of the vegetable and animal kingdoms 41A 

CHAPTER VI.— ANALYTICAL CHEMISTRY. • 

Sect. 1. Analysis of Mixed Gases 41% 

Sect. 2. Analysis of Minerals 413 

Sect. 3. Analysis of Mineral Waters 414 

Appendix ; Glossary ; General Index ; Index of Plates 420 



NOTE. 

F. and Fahr. for Fahrenheit's thermometer.— T. refers to Tamer's' Chemistry.— 
W. to Webster's Chemistry, 3rd Ed.— L. to Liebig.— B. to Berzelius,— Eq. and Equi*' 
for Equivalent.— Symb. for Symbol or formula. 



INTRODUCTION 



Science is classified knowledge. Physical of Natural 
Science is the knowledge of the material world. The defi- 
nition of matter embraces two properties, without which we 
cannot even conceive of its existence. These properties are 
extension, which includes length, breadth, and # thickness, and 
impenetrability, or the impossibility that any two portions of 
matter should occupy the same space. There are other prop- 
erties, which do not necessarily enter into our conception of 
matter, but which universally belong to it, such as gravitation, 
inertia, mobility, etc. 

Natural Science consists of three great branches, which 
are characterized chiefly by peculiar methods of investigation. 

I. Natural Philosophy employs the method of general 
physics ; that is, it observes, for example, the gravitation of a 
stone let fall to the ground, and, neglecting the other proper- 
ties of the stone, observes the same property in other bodies, 
and generalizes the phenomena under a law. It is therefore 
conversant with general laws, but not with all the general 
aws, for its observation is restricted to the phenomena of 
perceptible distance. By this we mean that it leaves to the 
chemist all those phenomena which arise from the action of 
the invisible atoms of matter upon each other, and attends 
only to those which belong to bodies of perceptible size. 
With a few observations and experiments for data, it depends 
for discovery upon calculation, and its character is therefore 
eminently mathematical. Its object :*s a knowledge of the 
laws of motions and forces. 



22 



INTRODUCTION. 



II. Chemistry employs, in part, the method of general 
physics, and, in part, the method of particular physics. By 
the latter, we mean that its object is, in part, to describe 
particular bodies or substances, by giving an account of the 
various properties of each one, before calling the attention to 
another. It invites our attention to the phenomena only of 
imperceptible distance. With some aid from calculation and 
observation, it depends for discovery chiefly upon experiment, 
and has therefore been called Experimental Philosophy. Its 
object is a knowledge of the constitution of substances and 
of the phenomena attending a change of constitution. 

III. Natural History employs the method of particular 
physics, observes the phenomena of perceptible distance, and 
depends for discovery chiefly upon observation, with some aid 
from experiment and calculation. Its object is a knowledge 
of natural objects. It embraces Zoology, or the study of 
animals; Botany, or the study of plants; Mineralogy, which 
treats of minerals; and Geology, which describes and accounts 
for the condition of the crust of the earth. The physiology 
of plants and animals is sometimes referred to Botany and 
Zoology respectively, and sometimes regarded as a fourth 
distinct branch of Natural Science. 

Plan of the Work. 

I. The constitution and the changes of the constitution 
of substances are intimately connected with the agency of 
heat, light, electricity, and galvanism, of which the two last- 
mentioned agents are supposed to be identical. Whether 
these agents are themselves substances, or mere properties 
of matter, is not certainly known. They have no appreciable 
weight, and are therefore called imponderable agents. They 
will form the subject of the First Part. 

II. The Second Part will treat of chemical affinity. This 
is the great agent to which all the phenomena of chemistry are 
referred. It is distinguished from gravitation by exerting its 
force between the particles of bodies, and from cohesion by 



INTRODUCTION. 23 

acting only between particles of different kinds or in different 
states of electricity. For example, a block of marble is made 
up of very small particles, each one of which is similar to the 
whole ; but each of these particles is composed of two others, 
carbonic acid and lime, different from each other, and from 
marble. When these particles of carbonic acid and lime are 
brought into close proximity to each other, they assume dif- 
ferent electrical statee, and combine by the force of chemical 
affinity, and form particles of marble. Cohesion then attaches 
them to each other as fast as formed, and thus the block is 
formed. Gravity acts upon it in the mass. The carbonic 
acid and the lime are called the component particles. When 
these combine, they form the integrant particles. Hence 
Chemistry is defined to be that science the object of which is, 
to examine the relations which affinity establishes between 
bodies, ascertain with precision the nature and constitution of 
the compounds it produces and determine the laws by which 
ts action is regulated. 

It is the object of Natural Philosophy to examine the sen- 
sible motions and mutual relations of bodies in masses, con* 
sequent upon gravity. 

Chemistry investigates the constitution and qualities of 
bodies as they stand related to chemical affinity. 

III. The Third Part will comprise a description of sub- 
stances, which will be arranged in two general divisions : The 
first will embrace the elements and those compound sub- 
stances which can be formed in the laboratory. These are 
chemical substances. The second division will embrace 
natural substances, or animal and vegetable compounds, 
which have been formed by natural agencies. 

Chemists divide substances into simple and compound. A 
simple substance is one which never has been separated into 
two kinds of matter, or which has never been decomposed. 
There are about fifty-eight simple substances. A compound 
body is one which is composed of two or more simple bodies, 
of which there are many thousands. 



24 INTRODUCTION. 

The composition of bodies is ascertained by two methods ) 

1. By separating the body into its simple elements, which 
is called analysis ; and. 

2. By causing the elements to combine and form the body, 
which is called synthesis. 

Chemical substances are arranged in three general di- 
visions : 

I. Non-metallic elements, and their primary compounds 
with each other. 

II. Metals, and their primary compounds. 

III. Salts, or secondary compounds. 

In the arrangement of the simple substances and their 
primary compounds, the logical order is pursued; that is, 
after describing one substance, the rest are described with the 
compounds which they form with those previously described 

The Salts are divided into four orders : 

I. Oxy-salts, or those salts the acid or base of which 13 an 
oxidized substanee. 

II. Hydro-salts. This order includes no salt, the acid or 
base of which does not contain hydrogen. 

III. Sulphur-salts, or those salts, of which the electro- 
oositive or electro-negative ingredient is a sulphuret. 

IV. Haloid-salts, including none, the electro-positive or 
electro-negative ingredient of which is not haloidal, i, e,. 
analogous in composition to sea salt 



CHEMISTRY 



PART I. 
IMPONDERABLE AGENTS. 

CHAPTER I. — CALORIC. 

The word heat has two meanings. It is the sensation which 
we experience when we touch a hot body ; or it is the cause 
of the sensation. In the first sense, it is an effect produced 
only upon animals. In the second, it is the cause of a great 
variety of effects in the mineral, vegetable, and animal king- 
doms. The word caloric (Lat. color) is used in the latter 
sense. Where there can be no ambiguity, the word heat is 
often retained in the same sense. Caloric exists in a free 
or sensible, and in a latent or insensible state. 

1. Sensible Caloric. In this state, caloric is capable of 
producing the sensation of heat, and of expanding bodies. 
It has sometimes been called the caloric of temperature. 
Temperature expresses the power of exciting the sensation, 
and is proportioned to the quantity of free caloric. A high 
temperature is owing to a great quantity, and a low temper- 
ature to a small quantity. 

2. Insensible Caloric. In this condition, caloric produces 
no sensation, but exists, often in great quantity, in substances, 
without affecting their temperature, and appears to be com- 
bined with them. 

2 



26 Conduction of Caloric. 

* 
Sect. 1. Sensible Caloric. 

Communication of Sensible Caloric. 

The most important property of free caloric is its tendency 
to an equilibrium ; that is, a tendency to escape from hotter 
to colder bodies, so as to produce in all the same degree 
of temperature. This communication takes place in two 
ways — by conduction, and by radiation. 

I. Conduction. By this is meant the passage of caloric 

through a b@dy, from particle to particle. 

Experiment. Place bits of phosphorus along an iron rod, and apply 
heat to one end of it ; the progress of the caloric will be indicated by 
its igniting the phosphorus. 

The property in the body, on which this transmission 
depends, is called the conducting power. 

If one end of an iron rod be held in the fire, the sensation 
of heat will soon be experienced at the other extremity, in 
consequence of the conduction of caloric from particle to 
particle along the rod. If the rod be of glass, it will be 
much longer before any heat is felt. Hence different sub- 
stances conduct caloric with different degrees of facility. 

If two bodies are in contact, caloric may be conducted 
from one to the other. The more perfect the contact, other 
things being equal, the more rapid the conduction. This 
is the reason why a heated body, when grasped firmly by the 
hand, will burn it more severely than when held loosely. 

The contact of two solids with each other, or of a solid 
with a gas, is not so perfect as that of a solid with a liquid ; 
and hence the communication is more rapid in the latter 
case. When liquids are mixed with liquids, or gases with 
gases, the contact is still more perfect, and the caloric is 
more rapidly diffused through the whole. 

From the two facts which have been mentioned, it follows 
that the rapidity of conduction from a heated to a cold body 
depends upon the conducting power of each substance, ana 
tJie closeness of contact. 



Conducting Power of Solids. 



27 



Exp. Plunge a heated iron into cold water, and again, equally heated, 
into mercury. In the latter case, it will cool more rapidly ; for, while 
the heat is conducted with equal facility in both cases from the interior 
to the surface, it is taken from the surface more rapidly by the mercury 
than by the water. 

Exp. Plunge into mercury two equal balls, one of iron and the othex 
of marble, heated to the same temperature. The iron ball will cool the. 
more rapidly, because the caloric is more freely conducted from its in 
terior to its surface. 

Exp. Plunge the iron ball into mercury, and the marble into water. 
'The iron will cool more rapidly, for two reasons; the heat will come 
to its surface more freely, and be taken off by the mercury more 
rapidly, iron and mercury being each better conductors than marble 
©r water. 

Of the different forms of matter, solids are better conduct- 
ors of caloric than liquids, and liquids than gases. 

1. Conducting Power of Solids. The power of solids to 
conduct caloric varies greatly in different substances. 

This fact may be shown by Fig. 1. 

the conductometer, (Fig. 1,) 
which consists of a tin or iron 
case, in which there may be 
inserted small solid cylinders of 
the same dimensions, but of 
different materials. 

Exp. Place upon one end of each, bits of phosphorus, and apply to 
the other ends the same degree of heat by placing the case over boiling 
water. The caloric will be conducted along from one extremity of 
each to the other, and those substances which conduct most rapidly will 
first ignite the phosphorus. 

According to the experiments of M. Despretz, if the con- 
ducting power of 

Gold be represented by 1000 
Silver will be . . . 973 

Copper 89S.2 

Platinum 381 

Iron 374.3 

Zinc .363 

Metals generally are the best conductors of caloric, while 
furs and porous substances are the poorest conductors. 

The conducting power of stones is next to that of the 
metals, and crystalline stones are better conductors than those 
which are not crystallized. 




Tin . . 


303.9 


Lead . . 


179.6 


Marble . 


. 23.6 


Porcelain 


. 12.2 


Fine clay 


. 11.4 



28 Caloric — Conducting Power of Liquids, 

The earths are very bad conductors of caloric. Bricks, 
glass, baked wood and charcoal, are still poorer ; while silk 
hair, feathers and down, have a less conducting power than 
any other class of solids. 

Among the latter, the finer the fibre, th& less its conducting 
power. Hence the utility of fine wool and furs in the winter, t<? 
prevent the escape of caloric from the body ; while, in the sum. 
mer, we select those substances for our clothing which have a 
coarser fibre. In this we see the benevolence of God in furnish- 
ing those animals which inhabit the colder regions of the earth 
with finer clothing than those which inhabit warm climates. 
The fur of animals is also finer in winter than in summer. 

Snow and ice are poor conductors ; and hence, by a wise 
constitution, the earth in winter is rarely frozen to any con- 
siderable depth. The ice and snow keep it warm by pre- 
venting its vital heat from escaping. 

The conducting powers -of solids are generally in the ratio 
of their densities. Thus if a piece of metal be rendered more 
dense by hammering, there will be an increase^of its con- 
ducting power, and if its density be less, there will be a cor- 
responding diminution of this power. 

2. Conducting Power of Liquids. In liquids the conduct". 
ing power is much less than in solids. So feeble is it, that 
some, among whom is Count Rumford, have denied its ex- 
istence. But, notwithstanding the slight conducting power 
of liquids, heat can be diffused through them much more 
rapidly than through solids. This is effected by a motion 
among the particles, which brings them successively into 
contact with the heated surface. 

If, for example, heat is applied to the 
bottom of a vessel of water, (Fig. 2,) those 
particles of water which are in contact 
with the bottom, are soon heated, and con- 
sequently expanded and made lighter, so 
that they are forced to rise, in order to give 
place to the heavier cold particles, which 
fall to the bottom. The latter, in turn, are 
heated, and give place to others ; and thus 
the process continues until two currents 
are established, the one of heated particles 
rising to the surface, and the other of colder particles falling 
o the bottom. In this way all the water is soon heated by 




Conducting Power of Gases 



29 




Fisr . 4. 



direct contact with the bottom.* A little powdered amber or 
gum copal, put into the water, will indicate the direction 
of the currents. 

But if heat be applied to the top of the ves- Fig. 3. 

sel, the water at the bottom will remain cold, 
while that at the top is boiling. 

Exp. Suspend in a tin cup a hot cannon ball on the 
top of a jar of water, (Fig. 3,) at the bottom of which is 
a piece of ice. The water will boil rapidly at the top, 
while the ice remains unmelted. But if the ice is 
placed upon the top, and heat applied to the bottom, 
the ice will all be melted before the water can be 
made to boil. 

Exp. Or, burn ether (Fig. 4) on the top of a glass 
funnel filled with water, into which an air thermome- 
ter is cemented. The thermometer will be but slightly 
affected. A ring of tin should be placed on the top of 
the water, within half an inch of the sides of the fun- 
nel. The ether, poured within this ring, will burn, 
without the risk of breaking the glass. 

It has, however, been shown that liquids do 
conduct heat, independently of any intestine 
motion. But the power is very slight. 

?.. Conducting Power of Gases. Gases and vapors conduct 
heat very slightly, if at all. Liquids and gases are heated 
by a process called convection. The particles move easily 
upon each other, and are brought into direct contact with the 
heated surface, and convey away the heat. 

II. Radiation. If a heated body be suspended in the air, 
its caloric will be diffused both by the currents of air, which 
circulate to and from its surface, {convection,) and by the 
conducting power of the air. But if the hand be placed be- 
neath the heated body, a sensation of heat will be perceived, 
which is not 'jue to either of these causes, but to the direct 
passage of the rays through the air. 

For if a heated body be suspended in a vacuum, entirely 
removed from conducting substances, it will rapidly cool 




* A Florence flask, or a glass tube, may be used for this experiment, 
and the water heated by a common tin lamp filled with alcohol. 



30 



lladiation of Caloric 



down to the same temperature with surrounding bodies 
Caloric, which is thus thrown off from heated bodies in al 
directions, like rays of light from the sun, is called radian, 
caloric. 

1. If a thermometer be placed at the distance of two 
inches from a heated body, it will be arlected but one fourth 
as much as at the distance of one inch; if it be placed at the 
distance of three inches, one ninth as much ; if at four inches, 
one sixteenth as much ; at five inches, one twenty-fifth, etc. 
Hence, in consequence of a radiation in all directions, the 
intensity of the heat is in the inverse ratio of the square of 
the distance. The intensity of light and the force of gravi- 
tation follow the same law. 

2. The degree of radiation, and consequently the intensity 
of radiant heat, are greatly modified by the kind of surface. 
JBnght, polished surfaces do not radiate so rapidly as those 
which are dark and rough. 

Fig. 5. 



Exp. Take a square 
tin cup, a, (Fig. 5,) one 
side of which is bright, 
another rough, a third 
painted black, and the 
fourth painted white. 
Fill it with hot water, 
and bring an air ther- 
mometer, c, near each 
side. The rough and 
black surfaces will 
radiate more rapidly ^ 
than those which are == 
white and polished. 

If the rays of caloric are brought to a focus by the mirror b, the dif 
ferent degrees of caloric from the several surfaces will be much more 
evident.* 

The greater radiating power of rough surfaces is supposed 
to be due to the great number of radiating points; or perhaps 

* The late experiments of Melloni do not seem to confirm this view 
By using a cup of marble, whose external surfaces were differently 
prepared, the first polished, the second smooth but tarnished, the third 
streaked in one direction, and the fourth in two, crossing each other at 
right angles, and filling the vessel with hot water, each of the sides 
projected the same quantity of radiant caloric. — Edin. P kilos. Jour 
XXVI. 299. 




Reflection of Caloric. 



31 



it may be owing to the greater amount of surface exposed 
within a given space. 

3. The rapidity of radiation also depends upon the differ- 
ence between the temperature of the radiating body and that 
PTthe surrounding bodies. Hence, with a given temperature 
f the latter, the higher the temperature of the radiating body, 
•.he more rapid the radiation. 

III. Disposition of radiant Caloric. Radiant caloric passes 
in right lines through a vacuum, through air and gases, with- 
out any apparent obstruction ; but when it falls upon solid or 
liquid substances, it is disposed of in three ways : 1. It re- 
bounds from the surface, or is reflected. 2. It enters into the 
substance, or is absorbed. 3. It passes through the body, or 
is transmitted. 

1. Reflection of Caloric. When radiant caloric falls upon 
bright, polished surfaces, it is mostly reflected in lines, which 
form angles with a perpendicular to the reflecting surface, 
equal to the angles formed by the same perpendicular, and 
the lines in which the rays went to the surface. 



Thus, let BAG (Fig. 6) be a smooth sur- 
face, S the incident ray, P the perpendicular 
to the surface, and R the reflected ray. The 
angle RAP is equal to the angle PAS. The 
angle PAS is called the angle of incidence, 
and PAR the angle of reflection. Light fol- 
lows the same law. If a concave surface be 
used, the rays of caloric will be reflected and 
brought to a focus. This may be shown by 
Iwo metallic mirrors, as in Fig. 7. a and b 

Fig. 7. 



Figr. 6. 



B 



.R 




^ 




32 Absorption of Caloric. 

are two reflectors of polished metal, (brass or tin,) 12 inches 
in diameter, and segments of a sphere of 9 inches radius 
Place them at any convenient distance apart, from 6 to 15 
feet. If a heated ball of iron be placed in the focus of a, and 
an air thermometer in that of 6, the caloric will first radiate 
to the surface of a, and then be reflected in parallel lines to 
„be surface of b, whence the rays will be reflected to the focus 
in which the bulb of the thermometer is placed, and will 
cause the liquid to descend, showing an increase of tempera- 
ture. If phosphorus be placed in the focus, it will be ignited. 
If snow be substituted for the heated ball, the thermometer 
will show, by the rise of the liquid, a diminution of tempera- 
ture. As bright, polished surfaces reflect most of the calorific 
rays which fail upon them, we can see the reason why they 
are not easily heated. 

2. Absorption of Caloric. When radiant caloric falls upon 
rough, opaque substances, it is mostly absorbed ; that is, it 
passes directly into the substance, and renders it hot : soms 
of the rays are also reflected. 

The power of absorption, as well as of radiation and re- 
flection, depends mostly upon the surface. Those surfaces 
which reflect most, radiate and absorb least, and those which 
radiate and absorb most, reflect least. The power of absorp- 
tion and that of radiation are equal ; and as each increases, 
the power of reflection diminishes. 

The color of, the^ surface also affects the power of absorp- 
tion. 4)f. Stark has shown that black surfaces, other things 
being equal, absorb the most; dark green next to black; 
scarlet next ; and white the least of all colors.* 

Exp. This fact may be shown by placing strips of cloth of different 
colors upon snow, exposed to the sun's rays ; the black will be found 
to sink into the snow to the greatest, and the white to the least, depth, 
because the black absorbs tbe rays which melt the snow, and the white 
reflects them. Hence the advantage of painting rooms white, or of 
whitewashing them : the rays of caloric are thus kept passing from 
side to side, without being absorbed and conducted away. 

3. Transmission of Caloric. When radiant caloric falls 
upon the surface of transparent solid or liquid bodies, it 
passes through them in a slight degree. 

It passes easily through air and other gaseous substances, 
without sensibly affecting them; but glass and crystalline 

* Recent experiments seem to disprove this doctrine ; a black surface is 
rougher. ^^ 



Theories of Radiation. 33 

substances intercept most of the rays. Prof. Leslie contends 
that glass does not permit the rays to pass directly through it, 
but absorbs them at one surface, and transmits them to the 
other by conduction, from which they are again radiated. 
This opinion is supported by Dr. Brewster by an argument 
drawn from his optical researches. But the experiments of 
De la Roche lead to a different conclusion — that the calorific 
rays do pass through glass, although slowly. This opinion is 
supported by other chemists. 

The radiant caloric which is associated with solar light 
passes readily* through glass and other transparent bodies. 
The caloric, in this case, seems to be modified by its con- 
nection with light, and may be collected into a focus with the 
light, as in the case of a burning-glass. Caloric, thus asso 
ciated, suffers refraction in passing from one medium to 
another, and in general is subject to the same laws with light. 

IV. Theories of Radiation. Of the various theories to 
account for radiation, only tioo seem worthy of notice. 

I. The theory of Pictet supposes that a hot body will 
radiate caloric to surrounding colder bodies, until the equi- 
librium is restored, and then cease. 

2. The theory of Prevost supposes that all bodies, what- 
ever be their temperature, are constantly giving out and 
receiving radiant caloric. Y/hen a body is giving out more 
rays than it is receiving, it is cooling. When it gives and 
receives an equal number, its temperature remains stationary, 
and is in equilibrium with surrounding bodies. When it 
receives more rays than it gives orF, its temperature is in- 
creasing. On this theory, all bodies — the polar ice, as well 
asthe burning sands of the tropics — are constantly radiating 
and absorbing caloric. 

Although most of the phenomena of radiation may be 
explained on both theories, preference is generally given to 
that of Prevost. The ground of this preference is found in 
the close analogy between the laws of light and heat. It is 
well known that luminous bodies continually exchange rays. 
A feeble light sends rays to one of greater intensity, and the 
quantity of rays emitted by each does not seem to be affected 
2* 



31 Application of ike Theory of. Prcvost. 

by the vicinity of other luminous bodies. In like manner a* 
bodies are supposed continually to exchange rays of caloric, 

V. Application of the Theory of Prevost to the Explana* 
Hon of various Phenomena.. 

1. In the experiments with the mirrors, if the ball in the 
focus of one mirror is of the same temperature with the 
thermometer in that of the other, and with surrounding 
objects, the thermometer will remain stationary, because it 
receives from the ball the same quantity of % rays which it 
sends to it; but if the temperature of the ball be raised above 
that of the surrounding objects, the thermometer will receive 
more rays than it imparts, and will consequently show an 
increase of temperature. If ice be substituted for the ball, 
the thermometer will show a diminution of temperature, be- 
cause it gives out more rays than it receives. 

When ice is placed in the focus of a mirror, there is an 
apparent radiation of cold. But on this theory it is easily 
explained, and is what might be expected previous to experi- 
ment.* Cold is a negative terra, merely expressing the 
absence, in a greater or less degree, of caloric. 

2. The formation' of dew depends upon radiation, and is 
satisfactorily accounted for by this theory. The earth, during 
the day, becomes heated by absorbing the sun's rays, and the 
moisture is driven off into the air. During the night, it radi- 
ates more caloric than it receives, and becomes colder than 
the surrounding atmosphere. Successive strata of air charged 
with moisture, come in contact with the earth, and the 
moisture is condensed in the form of dew. 

The quantity of dew will therefore depend upon the radi- 
ating power of the surface, and the quantity of moisture in 
the air; the more rapid the radiation, the more dew will be 
formed. There is more dew upon grass and leaves than 
upon stones; and the thermometer will sink 15° or 20° lower, 
when placed upon grass, than when suspended in the air, or 
laid on polished surfaces. In India, ice is formed by ex- 
posing water in pans in a clear night, when the temperature 

* See Turner, 6th edition, p. 13, note 



Cooling of Bodies. 35 

of the air is never down to the freezing point But why is 
there no dew in a cloudy night 1 Because the clouds reflect 
back the radiant caloric to the earth, which therefore cannot 
become cooler than the air. In a clear night, there is no 
such interchange of rays, and the caloric passes off into the 
regions of space.* 

VI. Cooling of Bodies. The cooling of a hot body is 
effected in two ways, already noticed. When surrounded by 
solid bodies in contact with it, the heat is carried off by 
conduction, and the velocity of cooling will depend upon the 
conducting power. When the heated body is immersed in 
jiquids, the same is true to some extent, although much de- 
pends upon the mobility of the particles. But when sur- 
rounded by gases, the cooling takes place by means of con- 
duction and radiation, and in a vacuum, by radiation alone. 

Velocity of cooling means the number of degrees lost in a 
given time. Law of cooling refers to the relation which the 
velocities of equal successive periods bear to one another. 
The higher the temperature, other things being equal, the 
greater the velocity. If a body heated to 1000° lose 100° 
during the first second, Newton inferred that it would lose 
yV of the remainder, or 90°, during the next second, 81° the 
next, 72.9° the next, and 65.6° the next. These numbers 
form a geometrical series, whose ratio is 1.111 ; and, though 
the law is not universal, it holds true, when the temperature 
is but a little elevated above the air. 

VII. Practical Application of the Laws of Conducted and 
Radiant Caloric. The material for windows should be a bad 
conductor of heat, as well as transparent ; hence glass is best 
adapted to the purpose. Glass also admits solar heat, while 
it prevents the escape of artificial heat. Double walls, doors, 
and windows, add to the warmth of buildings, because they 
confine between them a stratum of air, which, when not in 
motion, is a good non-conductor. Snow, furs, woollens, etc., 
are better non-conductors, because they enelose air. Stoves 
which are rough radiate more heat than those which are 



* The quantity of dew seems to depend also upon the difference be- 
tween the temperature of the atmosphere and that of the earth 



86 Effects of Free Caloric. 

polished. As the temperature of the human body usually 
exceeds that of the atmosphere, the object of clothing in 
cold weather is to retain the natural warmth ; and hence ii 
Is made of good non-conductors. In hot weather, clothing 
should conduct off the heat more freely. Also, under a hot 
sun, a black dress is more uncomfortable than one of light 
color. Many articles employed in the common uses of life 
are selected with reference to their conducting and radiating 
properties, as materials for furnaces, culinary apparatus, etc. 

Effects of Free Caloric. 

The phenomena which may be ascribed to caloric as an 
agent, and which may therefore be classified as its effects, 
are numerous : some of these effects will now be enumerated. 

The most remarkable property of caloric, as we have seen, 
is the repulsion, which exists among its particles, by which 
it tends to an equilibrium, or to bring all substances to the 
same degree of temperature. This property enables it to 
penetrate all bodies, and, by its accumulation, to separate the 
integrant molecules from each other. It thus acts in oppo- 
sition to cohesive attraction ; hence it may be stated as a 
general law, that 

I. Caloric expands all bodies; liquids more than solids, 
and gases more than either. 

1. Caloric expands solids. This may be shown by fitting 
an iron cylinder to an aperture, so that it will just slide 
through ; heat it, and it will be too large to pass through. 

2. Equal degrees of caloric expand some solids more than 
others. This may be shown by an instrument called a 
pyrometer, or fire measurer. 

Fig. 8 represents this instrument. It is furnished wi.h 
several rods, as iron, brass, copper, lead, and glass. 

BB, posts standing in A, and secured from spreading apart 
Dy the two bars CC. G, a thumbscrew, passing through the 
post B, and entering one end of the rod D, holds it against 
a lever at the other end ; as the rod is heated, it expands and 
presses against the lever, which raises E, at the end of which 
is a cord passing up, over the hub of the index, and down 



Expansion of Solids. 



37 



again to the balance rod F; E is raised by the expansion of 
the rod D ; F falls, drawing the cord, and giving motion to the 
tiand. 

Fig. 8. 




The following substances, when heated from 32° to 212° 
Fahr., are elongated as follows : 

• Flint glass, . . . . tsVs °^ * ts * en g tn 

Iron, F -£r 

Copper, ^ T 

Brass, -^ 

Lead, ^ 

3. Equal increments, or additions of caloric, at different 
temperatures, do not expand the same solid equally. 

That is, the expansion of a brass or iron rod will be much 
greater between 500° and 600°, than between 100° and 200°, 
or than between 200° and 300°. The higher the tempera- 
ture, the greater the expansion, with equal additions of 
caloric. This results from the fact that the power of cohe- 
eion is constantly diminished, the farther the integrant parti 
cles are removed from each other by heat. 

4. TJie expansion of some solids is more uniform than 
others, with equal additions of caloric. The expansions of 
the more infusible solids are uniform within certain limits 
From 32° to 122°, their expansion is equal to that between 



as 



Expansion of Liquids. 



Fig, 




122° and 212°. But above 212°, the higher the temperature . 
the greater the expansion, for equal additions of caloric. 

II. Caloric expands liquids more than solids. 

1. This fact may be illustrated by heating a 
column of water in a glass tube, and an iron rod 
of the same dimensions, by a spirit lamp ; the water 
will rise in the tube, while the iron will scarcely be 
affected. The reason is, that the cohesive at- 
traction in liquids is nearly destroyed. 

Exp. Plange a common thermometer into a jar of hot 
water, (Fig. 9.) The bulb of the thermometer will be ex- 
panded, and its capacity increased, but the mercury will 
be more expanded, and will rise in the tube. 

Fig. 10. 

2. Equal increments of caloric ex- 
pand some liquids more than others. 
This may be illustrated by partially 
filling several glass tubes furnished 
with bulbs with different liquids, and 
placing them in hot water; as the 
liquids expand, they will rise to dif- 
ferent heights in the tubes, as shown 
in Fig. 10. 

3. Equal additions of caloric, at different temperatures, 
do not expand the same liquids equally. The same law holds 
here as in the case of solids — the higher the temperature, the 
greater the expansion for equal amounts of heat ; and those 
liquids also which expand the least are more* uniform within 
certain limits. Apparent exceptions to the general law are 
found in the case of some liquids, near the point of con- 
gelation. Water expands by a diminution of temperature, 
and contracts by an addition of caloric, between the freezing 
point and 40° Fahr 

III. Caloric expands gases more than 
solids or liquids. 

1. The expansion of air may be shown by 
simply inverting a glass tube terminated by a 
bulb, and partly filled with water , t (Fig. 11,) 
in a vessel of the same liquid : on heating the 
bulb, the air will expand, and expel the liquid 
from the tube ; or by holding a bladder partly 




Fig. 11. 




Expansion of Gases. 39 

filled with air near the fire, the air will soon expand, fill the 
bladder, and even burst it.* 

2. All gases, at any temperature, are expanded equally 
by equal additions of caloric. In this respect, gases differ 
from solids and liquids. If, therefore, we can ascertain the 
expansion of one gas for a given number of degrees, we may 
know that of all others. The law of the expansion of air 
has been determined by Gay Lussac, who found that a given 
quantity of dry air dilates to ¥ ^ of the volume it occupied 
at 32°, for the addition of each degree of Fahr. 

Theory of Expansion. This has been already noticed. In 
the case of solids, the integrant particles are held together 
by cohesive attraction, but the caloric, being self-repellent, 
has the effect to overcome this force, and to separate the 
particles from each other. f In case of liquids, cohesive at- 
traction is much more feeble ; it will therefore require less 
power to separate the particles, and hence they are more 
expansible than solids. Gases are still less under the influ- 
ence of cohesion, and hence are more expansible. In fact, 
the form which matter assumes seems to depend upon the 
relative force of caloric and cohesion. In solids, cohesion 
preponderates ; in gases, caloric ; but in perfect liquids, these 
forces are in equilibrium, (the caloric being in a combined, 
and not a sensible state.) 

IV. Apparent Exceptions. Allusion was made to water 
and some other substances as apparent exceptions to the 
general law that heat expands and cold contracts all bodies. 
Water continues to contract, until it arrives at 39°, and then 
begins to expand until congelation takes place. 



* So great is the tendency of air and other gases to expand, that, if 
a given portion be confined in a bladder, or in a very thin glass of a 
square form, and put under the exhausted receiver of an air pump, the 
same effect will be produced as when heat is applied ; the particles of 
gases seem to be wholly free from the influence of cohesive attraction, 
and expand by their own caloric when the pressure is removed. 

t On the supposition that caloric is material, the effect is easily ac 
counted for ; but though its particles repel each other, they must have 
a strong attraction for matter, or they could not be introduced into it 
Caloric, therefore, is the antagonist force »,o cohesive attraction, but 
possesses a powerful attraction for matter, peculiar to itself. 



40 The Force of Expansion. 

Exp. Take a glass tube, with a bulb at one end, fill it with warn 
water; and place it in a mixture of salt and snow. The water in ths 
tube will sink until it arrives at 39°, and then begin to rise until it 
arrives at 32°. The water, in becoming ice, will increase in bulk ^, 
and ice, in melting, will diminish in bulk -J^; hence, if the specific 4 
gravity of water is 10, ice will be 9. The maximum density of water 
is at 39° Fahr. 

V. The force of expansion, when water freezes, is very 
great. The Florentine academicians burst a hollow brass 
globe, whose cavity was only one inch in diameter, by freez- 
ing the water contained in it. This must have required a 
force equal to 27,720 pounds. Major Williams, in 1784-5, 
performed similar experiments at Quebec, by bursting bombs, 
which also illustrated the amazing force of water in the act- 
of congelation. 

In consequence of this expansive force, glass and earthen 
vessels are broken, by suffering water to freeze within them ; 
water pipes are burst; pavements are thrown up, and de- 
stroyed, and walls, especially in moist grounds, thrown 
down. 

Theory. The cause of this expansion is supposed to be 
due to crystallization. The particles, at 39°, seem to be 
endowed with a kind of polarity, and attract the edges of 
each other ; and, at 32°, they are arranged in ranks and files, 
which cross at angles of 60° and 120°, as may be seen when 
water is freezing in a saucer. This new arrangement of the 
particles is supposed to increase the bulk ; but, whether this 
hypothesis be correct or not, it seems best to explain the 
effect.* 

VI. Advantage of this Exception. The wisdom and be- 
nevolence of God are strikingly exhibited in this arrange- 
ment. Otherwise, all our rivers, and lakes, and the ocean 
itself, in cold climates, would become solid masses of ice! 

When a body of water is freezing, there are two currents 



* This hypothesis relieves us from the necessity of supposing a real 
exception to the laws of nature. The effect is due to the operation of 
another law, (crystallization,) to which the law of expansion gives 
place. For, after the crystallization is completed, the usual law pre- 
vails, and ice contracts, with the further reduction of temperature. Fis- 
sures are thus produced, in extreme cold weather, by the contraction 
of ice on ponds. 



Uses of the Law of Expansion. 41 

esv&liished, as in the case of boiling water. The surface 
gives off iis caloric to the air, and the particles become heavy, 
and sink down. This forces the warm particles below to 
rise. But at 39° these currents arc arrested, because the 
colder particles begin to expand, and remain at the top. As 
soon as they are frozen, a covering of ice prevents, in a great 
measure, the escape of caloric from beneath, and the process 
of freezing is greatly retarded. But, if the contraction ex- 
tended to the freezing point, the colder particles would con- 
tinue to fall to ihe bottom, until the whole should be brought 
to that point, ami then suddenly freeze; or, if they should 
freeze upon the surface, the ice would continue to sink down 
until the whole should become a solid mass. 

Hence, in cold climates, the rivers and lakes would be 
converted into solid ice, and all their inhabitants would be 
destroyed ! But, by this simple and beautiful arrangement, 
the ice is retained upon the. surface, and confines sufficient 
stores of caloric to preserve the inhabitants of the waters, and 
ender the coldest climates habitable by man. 

Water is not the only liquid which expands under the 
reduction of temperature ; as the same effect has been ob- 
served in a few others, which assume a highly crystalline 
structure, on becoming solid. Hence the exactness with 
which cast iron fills the mould, and the use of antimony in 
casting types. Mercury is a remarkable instance of the re- 
verse; for, when it freezes, it suffers a very great contrac- 
tion. 

VII. Practical Uses of the general Law of Expansion and 
Contraction. All kinds of machinery are, of course, affected 
by this law. It must be strictly regarded in the construction 
of delicate time-pieces. Great use is made of it in the band- 
ing of wheels ; the iron is heated, and fitted to the dimen- 
sions, and then suddenly cooled, so that, by its contraction, 
it presses with great force, and becomes immovably fixed. 
In riveting together iron plates for steam engine boilers, it is 
necessary to produce as close a joint as possible. This is 
effected by using the rivets red-hot ; the contraction, which 
the rivet undergoes in cooling, draws the plates together 
with a force which is only limited by the tenacity of the 
metal of which the rivet itself is made. 

M. Molard, a few years since, at Paris, availed himself of this 



42 Thermometers. 

principle, to restore to their perpendicular direction two opposite walla 
of a gallery, which had been pressed outward by incumbent weight 
Through holes in the walls, several strong iron bars were introduced, 
so as to cross the apartment, with the ends projecting ; upon Avhich 
strong iron plates were screwed. The bars were then heated, and, 
while hot, the plates were screwed up. On cooling, the bars con- 
tracted, and drew the walls together. By repeating this process several 
times, they were restored to their original position. Balloons were 
first sent up filled with air which had been expanded by Tie at. 

Winds. The phenomena of winds depend upon the expan- 
sion of the air by the heat of the sun. In this way the trade 
winds are produced. Land and sea breezes depend upon radi- 
ation and expansion. During the day, the earth is more 
heated than the water, and the air is more expanded, and 
rises up. This will produce currents of cold air from the 
water to the land, called sea breezes. During the night, tjie 
earth radiates caloric more rapidly than the water, the air be- 
comes cooler, and currents pass from the J and to the water. 
These are called land breezes. Winds are also produced in 
those deserts which become greatly heated during the day. 

Thermometers. But one of the most ingenious and useful 
applications of this law is to be found in the thermome- 
ter. Its invention is generally ascribed to Sanctorius, who 
flourished in the seventeenth century. Some asc_ribe it to 
Cornelius Drebel, and others to Galileo. 

1. Air Thermometers. The substance employed 
by Sanctorius was atmospheric air, by the expan- 
sion and contraction of which he was enabled to 
measure variations of temperature. His plan was 
very simple. The instrument consists of a glass 
tube, (Fig. 12,) open at one end, with a ball blown 
at the other ; enough of some colored liquid is 
poured in to fill half the tube, which is then in- 
verted in a vessel of the same liquid. The air in 
the bulb, by its expansion, causes the water in the 
tube to sink, and, by its contraction, the pressure of 
the atmosphere causes it to rise. By adapting a 
scale to the tube, the instrument is fitted for use.* 

On one account, air is the best substance for a thermometer, 

* This instrument is easily constructed by heating a glass tube in 
the fire, and blowing a bulb upon the end; then insert the open end i*i 
gome eolored liquid. 




Differential Thermometer, 



43 



because its expansions and contractions are equal, with equal 
additions of caloric. But there are two objections to the use 
of this instrument ; — it can be depended upon only when the 
barometer stands at a fixed point ; variations of atmospheric 
pressure materially affect the rise or fall of the liquid. The 
expansion of gases, also, with slight degrees of caloric, is so 
great, that the length of the tube for measuring high or low 
temperatures would render the instrument inconvenient in 
practice. 

2. Differential Thermometer. Sir J. Leslie, in 1804, con- 
structed a thermometer, in which air is used, which is not 
affected by atmospheric pressure. 

It consists of two glass balls, (Fig. 13,) 
joined together by a glass tube, bent twice 
at right angles. The balls contain air, but 
the tube is nearly filled with sulphuric acid, 
colored with carmine. To one leg of this 
tube is applied a scale. It is evident that no 
effect will be produced upon the liquid, if 
both balls are heated alike, because the air 
in both will suffer equal expansion; but the 
slightest difference between the temperature 
of the two balls, will instantly be indicated by 
the rise or fall of the liquid in the tube. 
Hence its only use is to detect slight variations of tempera- 
ture between two substances, or of two contiguous spots in 
the same atmosphere, in very delicate experiments, where 
caloric is reflected, or refracted to a focus. It is hence called 
the Differential Thermometer. 

A much more delicate instrument of this kind has been 
constructed by Dr. Howard, of Baltimore, in which the vapor 
of ether, or alcohol, in vacuo, is used instead of air. 

But if air expands too much, and is affected by pressure, so 
as to be unfitted for the common purposes of measuring the 
degrees of temperature, solid substances, on the other hand, 
expand too little. 

The substance most convenient is a liquid, and the object 
is, to find some liquid whose dilations are nearly equal with 
equal additions of caloric, and whose boiling and freezing 




44 Mercurial Thermometer. 

points are removed at the greatest distance from each other 
Alcohol and ether would answer this purpose very well in 
one respect, — they resist congelation to a very low tempera- 
ture, but boil much sooner than water. Mercury seems to be 
the only substance which will answer the necessary condi- 
tions. 

3. Mercurial Thermometer. This instrument Fig. 14. 
(Fig. 14) is constructed in the following manner : 
A tube is selected with a small bore, of uniform 
diameter, and a small ball is blown at one end. 
The air is then mostly expelled from the bulb, by 
holding it in a spirit lamp, and the end of the tube 
quickly inverted in a cup of clear, dry mercury. 
As the bulb cools, the atmosphere forces the mer- 
cury into the bulb, which fills it two thirds full ; 
the bulb is again heated, and the mercury rises up, 
nearly rilling the tube, and expelling the air. It is 
again inverted over mercury, when the bulb and 
one third of the tube are filled ; it is then heated 
until it boils, and fills the tube to the top. A fine flame is 
then darted from a blowpipe * upon the open extremity of 
the tube, so as to fuse the glass, and close the aperture 
before the mercury recedes. It is then said to be hermeti- 
cally sealed, and the space abandoned at the upper extremity 
of the tube, as it cools, is a vacuum. 

Graduation. This is effected by ascertaining two fixed points ; and, 
as water always freezes at the same temperature, and also boils at the 
same temperature, when the barometer stands at the same height, we 
have only to immerse the bulb and a part of the stem in melting snow, 
or water containing ice, and mark the point to which the mercury 
sinks. This is the freezing point. To fix the boiling point, distilled 
water should be used, and the barometer should stand at 30 inches. 
A small quantity of the water, not more than one inch in depth, and 
contained in a deep metallic vessel, is made to boil briskly, and tha 
point to which the mercury rises, is marked ; this is the boiling point 
These two points being fixed, the interval is variously divided into 
equal parts. 



* Fig. 15 represents the most common forms 
of the blowpipe. It consists of a brass or copper 
tube, tapering nearly to a point, through the small 
end of which the air is forced, either by placing 
the large end in the mouth, or by adapting to it a 
oair of bellows. 




Register Thermometer. 



45 



Newton first suggested a scale, in which 
the zero was placed at the freezing point, 
and the interval divided into 40 parts, or 
degrees. In Fahrenheit's thermometer, 
which is generally used in this country and 
in England, the zero is placed at 32° below 
the freezing point, and the interval between 
the freezing and the boiling points is divided 
into 180 parts, so that the boiling point of 
water is 212°. Fahrenheit fixed his zero 
by immersing the thermometer in a mixture 
of snow and salt. Reaumur's scale places 
the freezing point at zero, and the boiling at 
80°. De Lisle placed the boiling point at 
zero, and the freezing at 150° below; this 
is used in Russia. But the most convenient 
scale is that of Celsius, in which the freez- 
ing point is at zero, and the boiling at 100°, 
called the Centigrade thermometer ; this is 
used in France. The different scales are 
seen in Fig. 10. 

The scale is either marked on the tube 
by a diamond, or on ivory or paper, and at- 
tached to the tube. The degrees above the 
boiling and below the freezing points occupy 
equal spaces with those between these points. 
The temperature expressed by one scale can 
be reduced to that of another, by knowing 
the relation which exists between their de- 
grees. The lower part of the scale, in labo- 
ratory thermometers, (Fig. 14,) turns up by 
a hinge, so that the bulb can be immersed 
in corrosive liquids. 



Fig. 


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c 


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EL 

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O 


C 

a 
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190-f 

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160- 1 


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r-90 


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= -£0 






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- -70 


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: so-- 


140-1 

[30-1 
120-5 
110- 1 
100- 1 


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: 




so-: 


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: 


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90-1 
80-| 
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20- 1 
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- r 



Fig. 17. 
^ 



4. Register Thermometer. 
This instrument consists of 
two thermometer tubes, (Fig. 
17,) bent at right angles, and 
retaining a horizontal position. 
One tube contains alcohol, and 
the other mercury. A small piece of black enamel is placed 
in the tubes on the surface of each liquid. As the alcohol 
contracts by exposure to cold, the enamel follows it towards 



£ 



ijih 



40 



Pyrometers of Wedgwood and Daniell. 



the bulb ; but when it expands, the enamel remains stationary, 
and suffers the liquid to pass by it. When the mercury con- 
tracts, the enamel does not follow it ; but when the mercury 
expands, it is forced along. Consequently, it remains at the 
highest temperature. The enamel, in the tube of alcohol, 
will indicate the lowest, and that in the tube of mercury the 
highest, temperature during any given time. 

For measuring temperatures below -39° F., the freezing 
point of mercury, alcohol, or ether, must be employed ; for 
temperatures above 662°, no liquid can be used, as they are 
all either decomposed, or dissipated in vapors. For very high 
temperatures, therefore, some of the more infusible solids 
are used. The instruments for this purpose are called 

Pyrometers. This term is derived from two Greek words, 
signifying measurer of fire. 

1. Pyrometer of Wedgwood. This is founded on the 
property which clay possesses of contracting when strongly 
heated, without expanding when cooled ; but the indications 
of this instrument cannot be relied on, and it is seldom used. 

2. Pyrometer of Daniell. This instrument, the best now 
in use, consists of a bar of platinum enclosed in a case 7J. 
inches in depth, made of black lead : one end of the bar is 
fixed ; the other is made to move an index, as it is heated. 
This, however, is not perfectly accurate, owing to the greater 
expansion of the platinum, in high temperatures, with equal 
degrees of heat. Generally, these instruments depend upon 
the elongation of a metallic bar by heat ; and one of the best 
for illustration is described on page 37. 

3. On the same principle is the 
Metallic Thermometer of Brequet, 
(Fig. 18,) for temperatures between 
the freezing and boiling points of 
water. It consists of a slip of silver 
and one of platinum, united face to 
face with solder, and coiled into a 
spiral, d, one end of which, c, is 
fixed, while the other is connected 
with an index, e, which moves over 
a circular, graduated plate, f f 
This index is found to move over 
equal spaces with equal additions of 
caloric ; and so sensible is it to slight 



Fig. 18, 




Insensible Caloric. 47 

rariations, that when enclosed in a large receiver, which 
was rapidly exhausted by an air pump, it indicated a reduc- 
tion oi' temperature from 66° to 25° =41°, while a sensible 
mercurial thermometer fell only 36°. 

It will be readily seen that thermometers do not give- us 
the absolute, but only the relative quantity of caloric con- 
tained in bodies. The true zero, or that point where abso- 
lutely no caloric exists, is unknown. Some have conjectured 
that it is 1200° or 1400° below the freezing point of water. 
But it is mere conjecture ; nor is it known, on the other hand, 
how high a temperature might result from an accumulation 
of heat. Neither limit is known. The thermometers and 
other instruments measure only a few degrees, in the middle 
of a scale, whose extremities are indefinitely extended. 

Sect. 2. Insensible Caloric. 

Every one sees that a quart of water contains double the 
quantity of caloric which is contained in a pint of the same 
liquid, when the temperature of both is the same. This is 
called insensible caloric, because it does not affect the ther- 
mometer. 

Specific Caloric. But different quantities of caloric are 
required to raise equal weights of different substances to the 
same temperature ; and, conversely, different quantities are 
given out by them in cooling equally. Suppose, for example, 
that, on adding a given quantity of heat to a pound of water 
at 50°, the temperature will become 60°, — the addition of the 
same quantity to a pound of sperm oil at 50°, will raise the 
temperature to 70°, while a pound of powdered glass will be 
raised from 59° to 100° by the same quantity of caloric. 
The temperature is increased 10°, 20°, and 50°, in these dif- 
ferent substances; i. e., if the required temperature to which 
they shall be raised be given, the oil will require but half as 
much heat as the water, and the glass only one fifth as much. 
Specific heat is the relative quantity of caloric requisite to 
raise the temperature of substances equally; i. e., taking 
water for a standard at 1, the specific heat of sperm oil will 
be T 5 ^, and of p- wdered glass T 2 ^.* 

* The phrase capacity for caloric was formerly used, and was in- 



48 Methods of determining Specific Heat. 

In these experiments, a portion of caloric disappear? 
This portion has been called latent or combined caloric 
in reference to the theory mentioned in the note below 
The phrase insensible heat is preferred, as not involving any 

theory 

Methods of determining Specific Heat. Various methods 
have been employed to ascertain the specific heat of sub- 
stances. The most convenient method is to mix with the 
substances, all being at the same temperature, a given quantity 
of some liquid, as water, at some other given temperature, 
and observe the relative effects. Thus, as in the example 
given, a pound of water at 80° may be added to a pound of 
the same at 50°, and the resulting temperature will be the 
mean, 65° ; another pound of water at 80° to a pound of oil 
at 50°, and the resulting temperature will be 70° ; i. e., the 
oil will gain 20° while the water loses but 10°.; and again, a 
pound of water at 80° to a pound of glass at 50°, and the 
temperature of the mixture will be 75°, the glass gaining 25° 
by 5° loss of the water. Other and more difficult experi- 
ments are necessary to ascertain the specific heat of gases 
and of solid bodies. 

Laws of Specific Heat. The principal laws of specific 
heat are the following : — ■ 

1. At the same temperature, and, in the case of gases 
with the same pressure, the specific heat of each body is 
constant. 

2. The higher the temperature, and, in the case of gases, 
the less the pressure, the greater the specific heat of the same 
body. 

This is supposed to be owing to expansion. In gases, the 
specific heat varies with the density and elasticity ; the greater 
the density, the less the specific caloric ; and the greater the 
elasticity, the greater the specific caloric. 

3. A change of form is accompanied by a change of spe- 
cific caloric. The specific heat of a body, as it passes from 
a solid to a liquid state, is increased. It is also supposed to 

tended to convey the idea, that a portion of the heat enters into and is 
combined with substances in a latent state ; but this is hypothetical, 
wid the phrase specific heat is preferred, as involving merely a fact. 



Effects of Insensible Caloric: 49 

be increased by a change of the body from a liquid state to 
that of a gas or vapor. 

4. As each substance has a specific heat peculiar to itself, 
it follows that a change of constitution is accompanied by a 
change of specific heat. 

5. A change of specific heat is generally accompanied by 
a change of temperature. Thus the expansion of a gas, 
which increases its specific heat, diminishes its temperature 

As a practical inference from the doctrine of specific heat, 
it may be remarked, that much less fuel will be necessary to 
heat some substances than others. 

Effects of Insensible Caloric. 

These are liquefaction and vaporization.* 

I. Liquefaction. All bodies exist in one of three states, 
solid, liquid, or gaseous, and their forms seem to depend, as 
we have seen, (page 39,) upon the relative forces of cohe- 
sion and caloric. Hence, by the increase and diminution 
of either of these forces, we can cause the body to assume 
either of these states. If a solid be sufficiently heated, it will 
become liquid, and then gaseous. So general is this fact, 
that it may be stated as a law. 

1. Point of Liquefaction. The temperature at which 
liquefaction takes place, is called the melting point, or point 
of fusion, as that at which liquids solidify is termed the point 
of congelation. These points are identical ; but there is a 
very great difference in substances as to the degree of heat 
which is required to fuse them. Each substance has a fixed 
point of fusion and of congelation. 

2. Caloric of Fluidity. If a pound of ice, which is at 
32°, be melted in a pound of water at 172°, the temperature 
of the whole will not be at the mean of 102°, but at 32°, 
showing that 140° have been taken into a latent state, by the 
liquefaction of the ice. Generally, liquefaction is accom- 

* Classed as effects of insensible caloric, because the free caloric 
passes into an insensible state, which is essential to the process. 



60 Caloric- - Freezing Mixtures. 

panied by the conversion of free into insensible heat. The 
heat which thus disappears seems essential to the process of 
liquefaction, and is called the caloric ofjluidity. Its. quantity 
varies in different substances, as in the following table : — 

Ice . . . 140° Fahr. Beeswax . 175° Fahr. 
Sulphur . 143.68° " ' Zinc . . 490° 
Spermaceti 145° " Tin . . 500° " 

Lead . . 162° " Bismuth . 550° 

Irvine. 

When the process is reversed, in congelation, this insensi- 
ble caloric is thrown out in a free state. Thus the freezing 
of water produces heat. 

3. Freezing Mixtures. Liquefaction may be produced 
without the addition of heat, and hence the caloric of fluidity 
will be obtained, in part, from the temperature of the sub- 
stances melted, but chiefly from the surrounding bodies; a 
great degree of cold is thus often produced. On this princi- 
ple various freezing mixtures are contrived. The most com- 
mon method of producing cold is, to mix together equal 
quantities of fine salt and fresh fallen snow, or pounded ice. 
The salt melts the snow by its affinity for water, and the 
water dissolves the salt, so that both are liquefied. The degree 
of cold produced is 32° below the freezing point of water, 
or at zero. This led Fahrenheit to commence his scale at 
that point. Any other substance, which has a strong affinity 
for water, may be substituted for salt. The crystallized 
chloride of calcium is the best, because it produces the most 
rapid liquefaction. The following table, constructed by Mr 
Walker, contains the proportions of several substances to 
produce different degrees of cold. 

MIXTURES. height. Thermometer sinks ^^f 

Sea-salt 1 \ . ~ 

Snow . . . . . 2 i • • • to — 5 

Sea-salt 2 1 

Muriate of ammonia . 1> . . . to — 12° 

Snow . . . . 5 ) 

Sea-salt 5 \ 

Nitrate of ammonia . 5 > . . . to — 25° 

Snow 12) 

Muted sulphuric acid 2 J from + 32 o to _ 23 o 55deg 



Freezing Mixtures. 



51 






Concentrated muriatic acid 5 J from + ^ tQ _ 2r 59 deg 

Concentrated nitrous acid 4 > from+ 330 tQ . 

Snow 7 j ' 

Chloride of calcium . . 5i from+33 o to . 

Snow 4 J ' 

Fused potassa . . . . 4^, ^ 

Snow 3 j ' 

Freezing may also be effected by the rapid solution of 
salts. The following table exhibits the proportions, taken 
from Walker's essay in the Phil. Trans. 1795. The salts 
must be finely powdered and dry. 



■30 r 62 
■40° 72 



•51° 83 



Parts 
by Weight. 



Thermometer falls 



Deg. of Cold 
produced 



5 

16 



from +50° to + 10° 40 deg. 
from -f 50° to + 4° 46 



MIXTURES. 

Muriate of ammonia 
Nitrate of potassa 
Water .... 
Nitrate of ammonia 
Water . . . ;. 
Nitrate of ammonia 
Carbonate of soda 
Water .... 
Sulphate of soda . 
Diluted nitrous acid 
Sulphate of soda . 
Nitrate of ammonia 
Diluted nitrous acid 
Phosphate of soda 
Diluted nitrous acid 
Phosphate of soda 
Nitrate of ammonia 
Diluted nitrous acid 
Sulphate of soda . 
Muriatic acid . . 
Sulphate of soda . 
Diluted sulphuric acid 

In order to the greatest effect, the substances should b*? 
cooled in a freezing mixture before they are united. 

4. The degree of cold produced by these artificial pro- 
cesses, is limited. The greater the difference between the 
temperature of the air and that of the mixture, the more 
rapidly will the air communicate caloric to it ; and this soon 



from + 50° to— 7° 57 

2} from + 50° to— 3° 53 

5 > from + 50° to — 14° 64 
4 J from + 50° to- 

9 \ 



12° 62 



6 >from + 50 c 

8 

5 
5 



to — 21° 71 



1 from + 50° to 0° 50 
4 1 from + 50° to + 3° 47 



52 Vaporization — Ebullition. 

puts a limit to the degree of cold. According to Mr. Walker 
the greatest cold did not exceed 100° below the zero of 
Fahrenheit. But a more intense cold is produced by evapo* 
ration. 

5. No process, however, will deprive a body of all its 
caloric. Dr. Irvine has attempted to infer the absolute 
amount from the specific caloric of bodies ; thus ice contains 
y 1 ^ less specific caloric than water ; and, as this y 1 ^ is equal to 
140°, it is inferred, that water contains ten times the amount, 
or 1400° of caloric ; but the estimates made by different 
chemists vary from 900° to 8000°, which shows that but little 
confidence can be put in their calculations. 

II. Vaporization. By vaporization is meant'the conver 
sion of liquid and solid substances into vapor. It is generally 
supposed that, if sufficient caloric be applied, all substances 
are susceptible of this change. 

A gas differs from a vapor in the circumstance that it is 
not so easily condensed into a liquid : it retains its state at 
ordinary temperatures and pressures. " The only difference 
between gases and vapors is the relative forces with which 
they resist condensation." — T. 

Some substances yield vapor readily, and are called vola~ 
tile. Others sustain the strongest heat of furnaces, without 
volatilizing, and are hence said to bejixed in the fire. This 
difference seems to depend on the relative forces of cohesion 
and caloric. Liquids are more easily vaporized than solids ; 
and solids, with a i'ew exceptions, like camphor, assume the 
liquid state before they are converted into vapor. 

Liquids may be vaporized in two ways: 1. by ebullition; 
2. by evaporation. In the first case, there is a rapid produc- 
tion of vapor, causing commotion in the liquid; and in the 
second, the process is conducted silently, the vapor impercep- 
tibly passing off from the surface of the liquid. 

4 

Ebullition. 

1. Sowing Point. The temperature at which a liquid is 

converted by ebullition into a vapor, is called its boiling 

point. This point varies greatly in different liquids under tho 

same circumstances, and in the same liquid under different 



Ebullition. 



53 



degrees of pressure. But each liquid has a fixed boiling point, 
when all the circumstances are the same. 

2. The chief circumstance which modifies the boiling 
point of the same liquid, is the pressure of the atmosphere, 
A column of air, extending to the top of the atmosphere, 
presses upon every square inch of surface with a force equal 
to 15 lbs. This is sufficient to sustain a column of mercury 
30 inoiies, or a column of water 34 feet. But the pressure 
varies at different times on the surface of the earth; and as 
we ascend high mountains, the pressure diminishes rapidly. 
The instrument by which this variation is measured is called 
the 

Barometer, the principle of which may be illustrated by 
filling a glass tube, open at one end, and about 33 inches long, 
with mercury, and inverting the open end in a cup of the 
same liquid. (See Fig. 19.) The pressure of the atmos- 
phere on the surface will sustain the mercury in the tube to 
the height of from 27 to 31 inches. 

. When the barometer stands at 30 inches, ether boils at 
96°, alcohol at 176°, water at 212°, and mercury at 662°, F. 
If the barometer stand at 28 inches, all these substances will 
boil at a lower temperature, and if it rise to 31 inches, the 
boiling points will be raised. Hence the two following laws : 

1. As the pressure on the surface of liquids diminishes, 
their boiling temperatures diminish. Thus water heated to 
72°, and placed under the receiver of an air pump, will boil, 
on exhausting the air, if the temperature be preserved. 

Ether will boil violently, under an exhausted re- Fig. .19- 
ceiver, at the common temperature of the atmos- 
phere. 

Exp. 1. Fill the barometer tube a with mercury, (Fig. 19,) 
and invert it in a cup c of the same liquid ; then introduce a 
small quantity of ether. As soon as it reaches the vacuum 
r, it boils rapidly, and the vapor forces the mercury down the 
tube. 



Exp. 2. The pulse glass (Fig. 20) 
acts on the same principle. It is con- 
structed by blowing a bulb b on the end 
of a glass tube, in which a small open- 
»ng is made, and through this a similar 



Fig. 20. 




54 Influence of Pressure upon the Boiling Point. 

bulb a is blown on the other end. Some spirits of wine are now in 
troduced, and heated in the closed bulb a until the vapor escapes irons 
the aperture in b, when it is hermetically sealed. The heat of the nana 
upon either bulb is sufficient to cause violent ebullition. 

Ether boils in vacuo at — 44°, alcohol at 36°, and water 
at 72°, and liquids generally boil at temperatures 140° less in 
vacuo than at the common pressure. 

It is owing to this fact, that intense cold can be produced 
by boiling ether in vacuo. Water, and even mercury 1 , under 
favorable circumstances, may be frozen. To render the 
experiment successful, there should be sulphuric acid in 
the receiver to absorb the vapor of ether, which, by its 
pressure, would otherwise soon prevent the ether from 
boiling. 

2. As the pressure on the surface of liquids increases, their 
boiling temperatures increase. When water is heated to the 
temperature of 212°, its force upon each square inch is equal 
to 15 lbs. As this is equal to the pressure of the atmosphere, 
it will, at this temperature, escape in vapor ; hence it cannot 
be heated in the open air above this point. But if the pres- 
sure be increased sufficiently, it may be heated to any extent, 

without exhibiting the phenamena-of ebullition. 

Fig. 21. 
Exp. Boil water in a Florence flask, (Fig. 21,) and cork 
it tight ; the ebullition will instantly cease, because the 
steam formed will press upon its surface; but by pouring on 
cold water, and condensing the steam, it will boil violently; 
pour on warm "water, and it will stop boiling. This is a 
convenient mode of illustrating both of the above laws : as 
the pressure is increased by the formation of steam, the 
boiling point is raised, while it is lowered by condensing 
the vapor and diminishing the pressure. This is called the 
culinary paradox. 

But, in order to exhibit the influence of pressure upon the 

boiling point, we must employ a strong metallic boiler, called 

a digester, which consists simply of a strong boiler furnished 

with stop-cocks and valves, and an apparatus to ascertain the 

temperature and pressure. Water confined in this boiler 

may be heated to a very high temperature without boiling 4 

but the steam which will be formed will endanger the boiler, 

before we can ascertain its greatest expansive force or pres* 

sure upon the liquid. 




MarceVs Digester. 



55 



For experiments on the pressure of Fig. 22. 

iteam, Marcet's digester (Fig. 22) is 
well adapted • a is a strong brass globe, 
into which a portion of mercury is poured, 
and then half filled with water; b a ba- 
rometer tube passing through a steam- 
tight collar to the bottom of the globe ; c 
is a thermometer graduated to 400° or 
500° ; d a stop-cock ; e a spirit lamp ; * 
and/' a brass stand, upon which the whole 
is supported. Upon the stop-cock d a 
steam gun may be screwed. When heat 
is applied, the pressure is measured by 
the height to which the mercury rises in 
the tube 6, and the temperature is ascer- 
tained at the same time by the thermome- 
ter c On the application of heat, as 
soon as the water boils, the thermometer 
will stand at 212°, and the pressure, of 
course, will be equal to one atmosphere, 
or 15 lbs. to the square inch. As the 
temperature increases to 217°, the pres- 
sure will elevate the mercury 5 inches, 
and at 242° about 30 inches, each degree of temperature 
raising the mercury about one inch. 

Absorption of Free Caloric in Ebullition. When water is 
.converted into steam, a great quantity of sensible heat is 
taken up into a latent state ; which, on condensation, again 
appears in a free state. 

If, for example, steam at 212° sufficient to form one pint 




* The spirit lamp is very useful for pro- 
ducing heat in the laboratory. It consists 
of a small glass lamp a, (Fig. 23.) the wick 
of which passes through a metallic collar c; 
b is an extinguisher, to prevent the wick 
from absorbing water when not in use. It is 
filled with alcohol, which burns in the same 
manner as oil, but does not yield any smoke. 
A common glass or tin lamp will answer a 
very good, purpose, using alcohol instead 
of oil. 



Fig. 23. 




56 Steam 

of water, be condensed in ten pints of water at 117°, th® 
temperature of the whole will be 212°; the ten pints will be 
elevated 95° : this is equivalent to raising the temperature of 
one pint 950°. The latent heat of steam is, therefore, 950° ; 
other substances are subject to the same law. Hence it may- 
be stated generally, that, in ebullition, heat is taken into a 
latent state, and given out on condensation. 

The latent heat of different vapors is various, as may be 
seen in the following table : — 

Latent Heat. 

Vapor of water at its boiling point . . . 967° 

Alcohol 442 

Ether 302.379 

Petroleum 177.87 

Oil of turpentine 177.87 

Nitric acid 531.99 

Liquid ammonia 837.28 

Vinegar \ 875 

Steam is formed, ordinarily, by ebullition. At the moment 
when water takes the state of vapor, in the open air, it has an 
expansive force equal to one atmosphere, or 15 lbs. on the 
sq. inch. If, then, it be disconnected. from water, its laws of 
expansion and. contraction, at all temperatures above 212°, 
are the same as all gaseous bodies. Equal increments of 
caloric expand it equally, and its expansion is in the ratio of 
the heating power ; for every degree of Fahrenheit's ther- 
mometer, it expands ¥ -|^ of what its volume would be at 32°, 
if it did not condense. It may be heated, like any gas, until 
it is red hot, if the vessel is sufficiently strong. But steam 
is usually formed in the boiler where water is present, and, as 
the temperature increases, fresh portions of steam are con- 
stantly added to that which is already formed, so that its 
expansive force increases in a much more rapid ratio. 

According to the experiments, of Dulong and Arago, if we 
take atmospheric pressure for unity, we shall find the pres* 
sure of steam at 233.96°, equal to I j atmospheres. 

250.52 equal to 2 atmospheres, or 301bs. to the sq. inch. 

275.18 " 3 " 45 

320.36 " 6 " 90 



Uses, of Steam. 57 

374 equal to 12 atmospheres, or 1801bs. to the sq. inch. 
435.56 •« 24 " 360 

486.59 " 40 " 600 " " 

510.60 " 50 x " 750 " " 

When steam, at a high temperature, is condensed in cold 
water, a loud, crackling noise is heard, which is due to the 
collapse of* the water, a vacuum being formed by the sudden 
condensation of the steam. 

£377. Let a jet of steam rush from the digester through a pipe into 
cold water. 

When liquids are converted into vapor, under high pres- 
sure, the vapor is very dense. If, then, it is allowed to escape 
from the orifice of the boiler, the hand may be held at a short 
distance without being burned, though the temperature of the 
steam, before it escapes, is several hundred degrees. 

This is due to its expansion, and the consequent absorption 
of its sensible caloric. When water is converted into steam 
at 212°, it absorbs 950° of caloric. If now it be condensed 
to 32°, it will give out 950° of latent, and 180° of sensible 
calorics 1130°. Now, if we take the same weight of steam, 
at a higher temperature, 250°, and condense it to 32°, it will 
give out 912° of insensible, and 218° of sensible caloric = 
1130°; hence the sum of the sensible and insensible caloric 
contained in equal weights of steam, is exactly the same at all 
temperatures =1130°. 

The absorption of caloric seems to perform a similar office 
in vaporization and liquefaction, being essential both to the 
formation of vapors and of liquids. 

Application of Steam to practical Purposes. 

1. It is used for warming rooms. For this purpose it is 
conveyed in pipes, and continues to heat the room until its 
caloric is nearly exhausted. It is then condensed to water, 
and gives out its latent caloric. 

Every cubic foot of steam in the boiler will heat 200 
feet of space to 70° or 80° ; and each square foot of steam 
pipe will warm 200 cubic feet of space. 

It is used for heating water-baths and dyeing-vats,* for 

a* 



53 Caloric. — Steam Engine 




bleaching cloth; for producing a vacuum by its condensa- 
tion; for various culinary purposes; also, for drying various 
substances, such as muslins, calicoes, gun-powder, etc. 

2. But its most important application is to the propelling 
of machinery : the instrument employed for this purpose is the 
steam engine; the invention of which is due to Capt. Savery. 

The principle of his invention may be illus- 
trated by a tube, with a ball blown at one end, 
(Fig. 24); fill this with water, and invert it in 
the same liquid, apply heat to the bulb, and, 
as soon as the water is at 212°, steam will be 
formed, and force the water out ; but, as soon as 
the steam comes in contact with the cold water 
in the vessel, it is suddenly condensed; a 
vacuum is formed, and the atmosphere forces 
the water with great violence up the tube, so 
as to fill the bulb. If a piston be fitted to 
the tube, it will constitute the instrument devised by Br 
Wollaston, except that the steam in his apparatus is con-, 
densed by putting the bulb into cold water. The atmos- 
phere presses the piston down, while it is raised by causing 
the water in the bulb'to boil. 

he moving power of the steam engine is the same as in 
this apparatus, but the steam is condensed in a separate ves- 
sel called the condenser : this constitutes the improvement of 
Watt, by which means, the temperature of the cylinder is 
never below 212° Fahr. 

8. The steam generator of Mr. Perkins sustains a pres- 
sure of 800, 1000, and even 15001bs. on the square inch. 
The steam is then so hot as to set fire to tow, and even ignite 
the generator at its orifice. At this very high temperature, 
it is about half as heavy as water. It is a remarkable fact, 
that, at such pressures, the steam will not rush through a 
small aperture, through which it will rush with great violence, 
and a roaring noise, when the temperature and pressure are 
diminished. Mr. Perkins thinks that 400 atmospheres, or 
6000 lbs. to the square inch, is the maximum of pressure; 
i. e., that under this pressure, water will remain liquid at any 
temperature, even at a white heat. The boiler of the gener- 
ator is small; and not more than a gallon of water is used at 
a time. 



Evaporation. 



59 




Steam Artillery. Mr. Perkins has succeeded in applying this amaz- 
ing force to the propelling of cannon balls. He states that sixty 41b. 
balls can be discharged in a minute, with the accuracy of a rifle 
musket, and to a proportional distance. A musket may also be made 
to throw from one hundred to a thousand balls per minute. It is great- 
ly to be hoped that his experiments will prove successful ; for, if such 
engines of death could be brought into the field of battle, few nations 
jvould be willing to settle their disputes in that way. Few would fight 
in the prospect of certain death. 

Fig. 25. 

Distillation. This process is 
conducted by converting liquids 
into vapor, which passes into a 
long, metallic tube, or worm, sur- 
rounded by cold water. The va- 
por is condensed, and the liquor 
runs off at the opposite extremity 
of the tube. Fig. 25 represents 
tills apparatus; a a copper boiler, 
b its head, connected with the 
worm, which is coiled in the refrigerator d. The vessel d is 
filled with cold water to condense the vapor in the worm as 
it passes through it. 

Evaporation. 
The only difference between evaporation and ebullition is, 
that the one takes place quietly, and the other with the ap- 
pearance of boiling. Evaporation takes place at all temper- 
atures, but ebullition at fixed temperatures. The former 
takes place, not only in all liquids, but in many solids, as 
camphor ; the latter is confined to liquids. 

1 . Evaporation is much more rapid in some liquids than in 
others, and it is always found that those liquids whose boiling 
points are lowest evaporate with the greatest rapidity. 

Thus alcohol, which boils at a lower temperature than 
water, evaporates also more freely, and ether, whose point 
of ebullition is yet lower than that of alcohol, evaporates 
with still greater rapidity. Also, if the temperature of the 
liquid be raised or lowered, the evaporation will be more or 
less rapid. 

2. Increase of pressure checks evaporation, and diminution 
of pressure promotes it ; thus water will evaporate much more 
rapidi.y in a vacuum,, 



80 Caloric. ~ Uses of Evaporation. 

This is precisely what we should expect from the fact 
just mentioned, that evaporation is most rapid in liquids 
whose boiling point is lowest; for the diminution of pressure 
lowers the boiling point. From the three facts which have 
been mentioned, it may be inferred that evaporation is more 
rapid as the distance between the boiling point and the tern- 
perature of the substance diminishes. 

The other circumstances that influence the process of 
evaporation are, 

3. Extent of Surface. As evaporation goes on from the 
surface, it is evident that, the greater the extent of surface, 
the more rapid the evaporation. 

4. State of the Atmosphere. If the atmosphere be already 
saturated with moisture, evaporation will be checked ; or, if 
the air remain still, it will soon become saturated, and the 
evaporation is promoted by the motion of the air. 

5. Absorption of Free Caloric by Evaporation. If a dish 
of water be placed in the exhausted receiver of an air pump, 
and another, of sulphuric acid, to absorb the vapor of the 
water, the. water will evaporate so rapidly, as to be frozen by 
the absorption of its sensible caloric* Hence the effect of 
evaporation is to produce cold; because the sensible caloric 
passes into an insensible state. 

Exp. This may be further illustrated by filling a small glass tube 
with water, and surrounding it with cotton wool. If the cotton wool 
ae soaked with ether, and a current of air, from a common bellows, be 
directed upon it, the water, in the course of a few moments, will congeal. 

Exp. A very satisfactory experiment 
is performed with the cryopkorus, an in- 
strument invented by Dr. Wollaston. 
It consists of two glass balls, (Fig. 26,) 
connected by a glass tube. Both balls 
are free from air ; but one of them con- 
tains a portion of distilled water. When 
the other ball is placed in a freezing mixture, so as to condense the 
watery vapor as fast as it formed, the evaporation is so rapid from the 

* The most intense cold which has been produced is the effect of 
evaporation If a large quantity of carbonic acid gas be condensed 
into a liquid by pressure, and suffered to escape through a small aper- 
ture, it will congeal by its own expansion; the solid acid thus formed 
will evaporate so rapidly in a vacuum, as to produce the cold of — 136° 
Fahr. At this temperature, the strongest alcohol becomes viscid, and 
r-rvntron alcohol beeomes frozen. 




Uses of Evaporation, 61 

mrface of the water in the other ball, as to freeze it in two or three 
minutes. 

6. Cause of Evaporation. The cause of evaporation is, 
doubtless, the same as that of ebullition — caloric; although 
some have attempted to account for it on the supposition of 
an affinity between the air and the evaporated liquid ; but 
evaporation in a vacuum is fatal to this hypothesis. 

7. Uses of Evaporation. It is well fitted for cooling 
apartments. All that is necessary for this purpose, is to 
sprinkle the floor with water. 

It moderates the heat of warm climates; hence places near 
large bodies of water are cooler in the summer than those 
more remote, and the greater the heat from the sun's rays, 
the more rapid the evaporation, and of course the greater 
quantity of sensible caloric goes into an insensible state. 

Evaporation not only takes place from the surface of water, 
but from the surface of the earth, and from plants and ani- 
mals; hence it tends to defend the animal, as well as the 
vegetable system, from external heat. When an animal is 
exposed to external heat, perspiration commences over the 
whole surface, and the liquid, in passing to a vapor, absorbs 
the sensible caloric. On this principle fire-kings subject 
themselves to a high temperature, with but little inconve- 
nience. The oven girls of Germany, also, often expose them- 
selves to a temperature of from 250° to 280°, and one girl 
breathed five minutes in an atmosphere of 325°. In these 
cases, water boils rapidly, and beef-steak is cooked in a 
few minutes. If, however, the air be moist, or the body be 
varnished, so as to prevent perspiration, the heat cannot be 
sustained for a moment. The heat produced by violent 
exercise is carried off in the same manner. 

But trie vital principle, doubtless, has much to do in forti- 
fying the system against the extremes of heat and cold ; for, 
although men may be subjected to a range of temperature 
of more than 400°,— from 350° above to 75° or 80° below 
2ero, — the temperature of their bodies does not vary five 



62 



Caloric. — Hygrometers. 



degrees, but remains stationary at 98° and 100°, during all 
,he varieties of external temperature. 

Evaporation often fills the air with deadly miasma. The 
fever and ague is supposed to be produced in this way. Con- 
siderable effect is also produced upon the bulk of gases, and 
it becomes a point of great interest to ascertain the amount, 
especially when delicate experiments are to be performed. 

The atmosphere, of course, always contains a portion of 
watery vapor. At the freezing point it contains ¥ ^ of its 
volume, and the higher the temperature, the more vapor is 
it capable of sustaining. The instruments for measuring the 
amount of vapor in the air, and other gases, are called 

Hygrometers. These vary in form, but may all be reduced 
to three principles. 

1. The first is founded on the property of some substances 
to elongate when placed in a moist atmosphere, and to con 
tract when dry. The human hair possesses this property in 
an eminent degree, and is the substance employed by Saus- 
sure. 

2. The second kind of hygrometer depends on the rapidity 
of evaporation, the temperature and pressure being the same ; 
the more vapor there is in the air, the slower will the process 
go forward. Leslie's hygrometer is constructed on this prin- 
ciple. 

3. The third kind depends on the fact that, if a cold body 
be introduced into moist air, the mois- 
ture will condense on it ; as is some- 
times seen on the surface of glass and 
earthen vessels filled with cold water, 
and is an indication of rain. The tem- 
perature at which the moisture is con- 
densed is called the dew point. On 
this principle the hygrometer of Prof. 
Daniell is constructed, and is the best 
instrument now in use. 

Thus, a b (Fig. 27) are two balls of 
glass, connected by a tube. The ball 
b is made of black glass, and contains 
a little ether, into which the bulb of a 
small thermometer is immersed. The 



Fig. 27, 




Explanation of Natural Phenomena. 63 

air is driven out of both bulbs, so that they contain nothing 
but ether and its vapor. On the standard c'there is a ther- 
mometer to measure the temperature of the air. 

Exp. Moisten a with ether, and the cold produced by its evaporation 
will condense the vapor of ether which rises up in b, and will cause a re- 
daction of its temperature. At the moment the dew begins to form on the 
glass b, the difference of temperature between b and c will show the dew 
point, and thus we ascertain the quantity of moisture in the atmosphere at 
that time. 

It will be seen that the dew point will vary with the quan- 
tity of water in the atmosphere. The difference between the 
temperature of the air and the dew point will be greatest 
when the air is very dry, and least when it is very moist. 

A more simple apparatus has been invented by Mr. Jones 
of London, which is said to give tolerably accurate results. 
It consists of a delicate Mercurial Thermometer, the bulb of 
which is about three quarters covered with muslin. Ether 
is placed on the muslin to produce cold, and the dew is de- 
posited on the uncovered portion of the bulb. The tempe- 
rature at which the dew begins to form, is indicated by the 
height of the mercury in the tube, as in an ordinary ther- 
mometer. 

The quantity of moisture in the atmosphere, as indicated 
by either of the above instruments, is dependent on the tem- 
perature and pressure ; hence the dew point will vary with 
the height to which we ascend. It is on this principle that 
air on the surface of the earth when it is carried up over high 
mountains, deposits a portion of water in the form of clouds, 
which are so often seen resting on the high summits. On 
this principle also rain is often produced by the rising up of 
currents of air. The air expands as the pressure is dimin- 
ished, grows colder, and its moisture is precipitated. 

Application of the Laws of Insensible Caloric to the Explana 
Hon of Natural Phenomena. 

1. We have seen that, when solids are converted into li- 
quids, they absorb large quantities of caloric. Hence the 
process of thawing, contrary to the common belief, is a 
freezing process. Ice, in becoming water, absorbs 140° of 
sensible calorio ; hence countries surrounded by water are 



64 Mxplanaiion of Natural Phenomena. 

cooler in the spring than those where less ice is formed dm 
ing the winter. * 

2. Liquids, in passing to vapors, absorb sensible caloric. 
In the vaporization of water, nearly 1000° of caloric are a!> 
sorbed. It is therefore a much more powerful cooling pro- 
cess than the liquefaction of ice; hence the heat of warm 
countries is greatly reduced by the constant formation of 
vapor. This is the reason why the transition from the cold 
of winter to the heat of summer is not sudden, but gradual ; 
the ice and the water cannot obtain caloric in sufficient 
quantities to convert them into vapor. 

3. When vapors and gases become liquids, they give out 
large quantities of caloric; hence it is usually warmer after 
a rain, a large quantity of caloric being evolved by the con« 
densation of the vapor in the atmosphere. If, however, the 
earth is dry and hot, the heat converts the water into vapor, 
and renders the air cooler. 

4. Liquids, in becoming solids, give out caloric; hence 
the process of freezing is a heating process. To prevent 
some substances from freezing, we have only to place them 
near those which congeal at a higher temperature ; thus 
water placed.in a cellar will prevent vegetables from freezing, 
because they require a lower temperature than water to 
freeze them ; before they reach the point of congelation, the 
freezing of the water renders its insensible caloric sensible, 
and prevents them from attaining it. 

By the process of converting water into ice, — a process 
constantly going forward when the thermometer stands at 
32° Fahr., — large quantities of caloric are thrown off into the 
atmosphere; hence the shores of a country are warmer in 
tjie winter than the interior; hence, too, the approach of the 
cold season is gradual, — the greatest degree of cold rarely 
occur? till after the winter solstice, twentieth of December 
Were thfse laws suspended, September and March would 
be of equal temperatures. June would be the warmest, and 
December the coldest month in tne year. 



f; 



Caloric. — Sources cf Caloric. 65 



Sect. 3. Sources of Caloric. 

The principal sources of caloric are, 

1. The sun. 

2. Chemical action, including electricity, galvanism, and 
combustion. 

3. Condensation by mechanical action, including percus- 
sion and friction. 

4. Vital action. 

1. Sun. The heat produced by the sun varies with the 
kind and color of the surface, according to principles already 
noticed. The temperature produced by their direct action is 
seldom more than 120° ; but, when the rays are concentrated 
by means of convex lenses, or concave mirrors, a very intense 
heat is produced. Lenses have been constructed concen- 
trating sufficient heat to melt some of the most refractory 
metals ; but the most intense heat, at any considerable dis- 
tance, is produced by several concave mirrors, which reflect 
the rays to one focus. Metals and minerals have thus been 
melted at the distance of 40 feet, and wood ignited at the 
distance of 120 feet from the mirrors. 

2. Chemical Action. Caloric is often produced *by chem 
ical and electrical action. A very great heat occurs in the 
phenomena of combustion, which may be denned to be the 
disengagement of light and heat in substances by chemical 
action. But the most intense heat is produced by voltaic or 
electrical action. 

3. Condensation. It has been already stated that sub- 
stances develop caloric by diminution of their bulk, as when 
gases pass to liquids and to solids. A fire is often kindled 
by rubbing pieces of dry wood' against each other; heavy 
machinery, if not properly oiled, often ignites woochj axle- 
trees of carriages are burned off; the sides of vessels are set 
on fire by the descent of the cable. The friction in these 
cases condenses the parts, and the caloric is developed. So, 



66 Nature of Caloric. 

when iron is struck with' a hammer several times, it becomes 
hot. Fire is also struck from steel with any hard substance, 
like flint. This is denominated percussion. 

4. Vital Action. The caloric developed by vital action 
has been shown to be due to the combination of the oxygen 
of the air, with the carbon and hydrogen of the worn-out 
tissues of the body. It is a process of slow combustion. 

Sources of Cold. The sources of cold are, liquefaction^ 
vaporization, and rarefaction. 

Sect. 4. Nature op Caloric. 

On this subject there are two theories. Sir H. Davy and 
some others considered caloric as a property of matter ; and 
Sir William Herschel and Prof. Airy have attempted to ex- 
plain its nature by supposing that there exists a subtile ether, 
which pervades all space and all matter, and that caloric is 
the effect of vibrations made in this fluid, somewhat similar 
to the vibrations of the air which produce the sensation of 
sound. This theory is called the undulatory theory, and is 
most favorably received by chemists. 

Sir Isaac Newton supposed that caloric was a subtile, ma- 
terial fluid. If caloric is material, it is matter under very 
peculiar circumstances. So far as we can determine, it pos- 
sesses few, if any, of the common properties of matter; its 
particles are self-repellent, opposed to cohesive attraction. 
If it is material, its particles must be exceedingly small, as 
they penetrate all other substances, however dense. They 
must also be influenced by gravity ; but no quantity of them, 
however great, possess the least appreciable weight. It pos- 
sesses neither extension nor impenetrability; but if it is mat* 
er, it must have these properties. 



Physical Properties of Light — Refraction. 67 



CHAPTER II. 

LIGHT. 

The physica, properties of light belong to the science of 
Optics, a branch of Natural Philosophy. But light has also 
chemical properties, which come within the province of 
Chemistry. 

I. Physical Properties of Light. Light is emitted from 
every visible point of a luminous object, and is equally dis- 
tributed on all sides, if not interrupted, diverging like radii 
drawn from the centre to the circumference of a sphere. It 
travels at the rate of 192,000 miles in a second, requiring 
about eight minutes to pass from the sun to our earth. Its 
velocity is so great, that the light emitted in the firing of a 
cannon, or a sky-rocket, will be seen by different spectators 
at the same instant, whatever may be their respective dis- 
tances from it ; the time required for light to travel one 
hundred or one thousand miles being inappreciable by our 
senses. When light falls upon any body, it is either reflected, 
transmitted and refracted^ or absorbed. 

II. Reflection. The reflection of light is influenced by 
the same circumstances as that of caloric, and follows the 
same laws ; the angles of incidence and reflection are equal 
(Fig. 6, page 31.) It is owing to the reflection of light that 
we are able to see the various objects in nature, an image 
of the object being formed by the reflected rays upon the 
retina of the eye. 

III. Refraction. When a ray passes from a rarer to a 
denser medium, as from air into water, it is refracted towards 
a perpendicular to the refracting surface : this property is 
called refrangibility. 

Thus (Fig. 28), I is the ray before it reaches the refract- 
ing surface 3. Instead of passing directly through to a, it 
is bent towards the perpendicular, to the surface p, and pro- 



Decomposition oj Light. 



Fig. 28. 



J 



ceeds to r. But in passing from a denser 
to a rarer medium, it is refracted from 
a perpendicular to the refracting sur- 
face. Thus, in passing from r, it is re- 
fracted at the surface towards I, instead 
of proceeding to d. Hence a stick 
partly in water appears bent. Objects 
viewed through some substances, as Ice- 
land spar, appear double in consequence of a double re 
fraction. ' 

IV. Decomposition of Light. Solar and stellar light con- 
tain three kinds of rays : — 

1. Colorific, or rays of color. 

2. Calorific, or rays of heat. 

3. Chemical rays, or those which produce chemica. 
effects. 

1. Colorific Rays. These may be separated into seven 
primary colors : red, orange, yellow, green, blue, indigo, and 
violet. 

Fig. 29. 




The instrument by which this separation is effected is a 
triangular prism (Fig. 29) of glass, ice, or any transparent 
substance. A beam of light r is admitted into a dark room, 
and, passing obliquely through two sides of the prism p, is 
refracted by both. The different colors are separated, be- 
cause some are refracted more than others ; and, instead of ? 
white spot after the beam passes through the prism, as at 8, 
there appears a long, colored surface c, called the solar spec- 
trum. 

Dr. Wollaston supposes that there are but four colors, viz. i 
red, green, blue, and violet, occupying spaces in the proper 
tion of 16, 23, 36, 28. 



Calorific Rays — Daguerreotype. 69 

According to Sir D. Brewster, there are but three colors, 
red, yellow, and blue, a mixture of which produces the others. 

The prismatic colors differ in their illuminating power. 
This is greatest in the yellow and green, and diminishes each 
way to the violet and red. 

2. Calorific Rays. The calorific rays exist in the greatest 
intensity in, and near the red rays, and diminish rapidly 
towards the violet ; the greatest heat is sometimes entirely 
without the red rays ; this, however, depends upon the kind 
of substances used to separate the rays ; in some cases, it is 
quite on the verge of the orange. The rej Tangibility , then, 
of the caloriiic rays is much less than that of the colorific. 
This is shown also by the fact that, when the solar rays are 
concentrated by a convex lens, the focus of heat is farther 
from the lens than that of light. 

3. Chemical Rays. On the side of the spectrum, a little 
beyond the violet, are invisible rays, which have a peculiar 
effect upon chemical changes. They are most powerful on 
the verge of the violet, and diminish towards the red. 

1. Fhotograpldc drawing depends upon the influence of 
these rays. 

Exp. Cover one side of a plate of glass with beeswax, colored with 
lamp-black, and draw a picture on it by removing the wax with a sharp 
point. If then a solution of salt in water be spread on a piece of white 
paper, and the nitrate of silver in solution poured upon it, the chloride 
of silver will be formed. Place the paper then over the glass, and the 
tun's rays passing through, where the wax is removed, will form a 
picture upon the paper, by changing the chloride black wherever they 
strike it. 

Exp. Soak apiece of white paper in a saturated solution of bichromate 
of potassa, dry it rapidly, and put it in a dark room. Place over it 
prints, dried plants, etc., and expose it to the sun ; the objects will be 
represented yellow on an orange ground. To fix the drawing, wash it 
carefully, to dissolve the salt which has not been acted upon by the 
light. The object will then appear white on an orange ground. 

If sulphate of indigo be used with the bichromate of 

potassa, it will give to the object and to the paper different 

shades of green. 

2. Daguerreotype. A method of fixing the images of ob- 
jects on metal has lately been devised by Daguerre 



70 isjagyictic Hays. 

Exp. Expose a plate of silvered copper, well cleaned with dilute 
nitric acid, to the vapor of iodine ; an extremely thin coat of iodide of 
silver will be formed. Place the plate in the Camera Obscura for eight 
or ten minutes, in such a position that the light may come from the 
object, and an image of it be formed on the plate; then expose it, at ar. 
angle of 4d°, to the vapor of mercury; heat it to 1G7° Fahr., and the 
images will appear. The plate should then be exposed to the action of 
hyposulphite of soda, and washed in a large quantity of distilled 
water.* 

Magnetic Kays. Dr. Morrichini, of Rome, discovered 
that the more refrangible rays possessed the property of 
rendering iron magnetic; Mrs. Somejville confirmed this 
statement by magnetizing a sewing needle with less than 
two hours' exposure to the violet rays ; but others have not 
been so successful, and it is questionable whether these rays 
possess this property. 

V. Absorption. The rays of light are separated by ab- 
sorption. When light falls upon a substance, more or less 
of it disappears like sensible caloric. 

1. The different colors are absorbed variously by different 
surfaces. This is the cause of the great variety of colors ; 
for, when all the rays are absorbed except the red, and these 
only reflected, the.body is red. Thus, in colored bodies, only 
a part of the rays can be reflected ; and to the admixture of 
the different colors in the reflected portion, is owing all the 
beautiful variety of color. 

2. The absorption of light varies with the chemical consti- 
tution ; hence, by the action of chemical agents upon each 
other, every variety of color can be produced at pleasure. 

Exp. Into a little chloride of calcium, in solution, pour a few drops 
of sulphuric acid ; a white solid will be formed. 

Exp. Into a dilute solution of persulphate of iron pour the tincture 
of gall ; fine black ink will be formed. 

Exp. Into an infusion of purple cabbage put a drop or two of sul- 
phuric acid ; a beautiful red Avill be produced. 

Exp. Nitrate of mercury and infusion of gall will form an oranga 
solor. 

Exp. Nitrate of lead and bydriodic acid, yellow. 

Exp. Vegetable infusion and an alkali, green. 

Exp. Aqua? ammonia and sulphate of copper, blue. 

Exp. Ferro-cyanide of potassa and sulphate of iron, indigo. 

Exp. Red and indigo, mixed, form violet. 

3. When all the rays are absorbed, so that none can be 
reflected, the body is black ; for the same reason, everything 

* See Jour. Franklin Inst. XXIV. 207. 



Light. — Ignition — Phosphorescence. 7 1 

is black in total darkness. If none of the rays are absorbed, 
and all are reflected, the body is white.* 

VI. Ignition and Incandescence. The phenomena of 
ignition and incandescence include all kinds of artificial 
light, which is obtained by the combinations of inflammable 
matter, or the heating of non-combustible bodies. Solids 
begin to emit light in the dark at 700°, and in the light at 
1000° F. Gases require a higher temperature; flame is in- 
candescent gas. The color of the rays depends upon the 
kind of substances and the degree of heat: the wmite light 
of oil, candles, etc., when transmitted through a prism, has 
but three primary colors — red, yellow and green. The 
dazzling light emitted by lime intensely heated, gives the 
prismatic colors almost as bright as the solar spectrum 
Different substances assume different colors when intensely 
heated. Chemical rays exist very feebly in most artificial 
light, but in the intense light of lime, under the compound 
blowpipe, they are more easily detected. 

VII. Phosphorescence. There are many substances in 
nature which possess the property of shining in the dark, 
without the emission of caloric. These are said to be phos- 
phorescent, and are known by the term phosphori, (although 
there is no phosphorus connected with the phenomena.) 

1. Solar Phosphori. Many bodies acquire this property on exposure 
to the solar rays for a few hours. Such, for example, is Canton's phos- 
phorus, a composition made by mixing three parts of calcined oyster 
shells with one of the flowers of sulphur, and exposing the mixture 
for an hour to a strong heat in a covered crucible. Chloride of cal- 
cium (Homberg's phosphorus) possesses the same property ; also, 
nitrate of lime, (Baldwin's phosphorus,) and a variety of other sub- 
stances, such as carbonate of baryta, strontia and lime, the diamond 
fluor-spar or chlorophane, apatite, boracic acid, etc. Scarcely any 
phosphori act unless they have been exposed to light. 

When phosphorescence ceases, it can be restored by a 
second exposure to the light, or by passing electric dis- 
charges through the substance. 

2. Phosphorescence from Moderate Heat. Chlorophane 
and several mineral substances require to be heated before 

* Colors have an important influence on the absorption and disen- 
gagement of odorous matters. White bodies are the least absorbent 
tnd dark the njost so. 



72 Photometers. 

they phosphoresce. Lime is a remarkable instance ; when 
heated, it gives out a dazzling white light, too intense to 
look upon without injury to the eyes. Light is also emitted 
during the crystallization of many salts, as the sulphate of 
potassa and fluoride of sodium. 

Exp. Put three drachms of the vitreous arsenous acid into a matrass, 
with an ounce and a half of hydrochloric acid, and half an ounce of 
water; boil the mixture for ten minutes, and then surfer it to cool 
slowly. When crystallization commences, each little crystal will be 
attended by a spark; on sudden agitation, great numbers of crystals 
shoot up, accompanied with an equal number of sparks ; if larger 
quantities are taken, and the vessel shaken at the right moment, the 
emission of light is so powerful as to illuminate a dark room. 

3. Animal and Vegetable Phosphori. Some animal and 
vegetable substances emit light at common temperatures, 
without exposure to the. sun's rays. This property is re- 
markable in some fish, as the mackerel : the light makes its 
appearance just before putrefaction commences, and ceases 
when it is completely established. Some species of decayed 
wood possess this property in a remarkable degree. 

VIII. Photometers. It is sometimes desirable to measure 
the intensity of light, emitted from different objects, and an 
instrument has been invented for this purpose, called the 
Photometer , or light measurer. The principal one employed 
for this purpose is that of Leslie. 

It consists of a very delicate and small differential ther- 
mometer, one bulb of which is made of black glass, and the 
whole is enclosed in a small glass tube. The white ball 
transmits all the light and heat, and is of course unaffected ; 
the black ball absorbs all the rays, and heats the air within, 
so as to cause the liquid to rise. Its action of course depends 
upon the heat produced by the absorption of light. 

Some objections to this instrument have been stated by 
Turner. 

Count Rumford's Photometer determines the comparative 
strength of lights, by a comparison of the shadows of bodies. 

Sources of Light. These are similar to those of caloric — 
the sun, stars, chemical action, mechanical action, and caloric, 

IX. Nature of Light. Light and caloric have been re- 
garded by some as identical. Newton supposed that light 



Electricity. 73 

was a material, subtile fluid, which emanated from luminous 
bodies in all directions in right lines, and produced the sen- 
sation of vision, by falling upon the retina of the eye; this 
16 termed the Newtonian theory. But Descartes, Huygens, 
and Euler, proposed a different theory, which has been lately 
revived by Sir John Herschel and Prof. Airy. This theory 
supposes that light is produced by vibrations in an elastic 
medium, which pervades all space, and that vision is the 
effect of these vibrations, meeting the retina, in the same 
manner as pulsations of air impress the nerve of hearing, 
and produce the sensation of sound. At present, the 
strongest evidence is in favor of this theory, which has 
received the name of the iindulatory theory. (See Sir J. 
HerscheFs article on Light in the Encyclopedia Metropol- 
itana.) Either of the above theories answers the purpose of 
classifying the facts, and it is not material which is adopted 



CHAPTER III. 

ELECTRICITY. 

The word electricity is derived from the Greek name for 
amber,* a substance which possessed the property of at- 
tracting light bodies when rubbed. 

1. If a piece of sealing-wax, or a glass rod, be rubbed with a 
dry woollen or silk cloth, each becomes capable of attracting 
and repelling light substances. In this state each is said 
to be electrified, or electrically excited. When friction is 
applied to many other substances, they exhibit similar phe- 
nomena. The cause of this attraction and repulsion is as- 
cribed to an agent called electricity, and when it is excited 
by friction, it is designated by the title of common elec- 
tricity. 

% If a plate of copper and a plate of zinc, having copper 
wires soldered to each, be immersed in acidulated water, 
and the ends of the wires brought into contact, they will 

* HXaxTQOV. 



74 Common Electricity. 

exhibit similar phenomena of attraction and repulsion. When 
electricity is excited in this way, there is always a chemical 
action between the metal and the liquid, and it is called 
Galvanism, in honor of Galvani, who made the discovery; 
also Voltaic electricity, from Volta, who first demonstrated 
its existence as independent of the animal system. 

Sect. 1. Common or Frictional Electricity. 

Common electricity is generally excited by the friction of 
one substance upon another. 

1. If a piece of sealing wax, or any resinous substance, be 
rubbed with a silk cloth, and a pith ball, suspended by a 
thread, be brought near it, the ball will be at first attracted, 
and then repelled. 

2. If a rod of glass, or other vitreous substance, be rubbed 
in a similar manner, and brought near the ball, it will attract 
it, while the sealing-wax will repel it. 

3. If two balls be each electrified by the sealing-wax, or 
by the glass, they will repel each other ; but if one is electri- 
fied by the wax, and the other by the glass, they will attract 
each other ; hence, when friction is applied to resinous and 
vitreous bodies, opposite effects are produced. The state 
induced by friction upon the glass, was called by Dr. Frank- 
lin positive, and that induced upon the wax negative, and the 
substances were said to be positively or negatively electrified. 

Theories. 1. Franklin supposed that electricity pervaded 
matter generally, and that friction tended to bring it upon 
the surface of bodies, or drive it from them ; that it was in 
its nature self-repellent, but possessed a powerful attraction 
for common matter; when a body was electrified positively, 
it had more than its share of electricity ; when it was electri- 
fied negatively, it had less than its natural portion. 

2. Du Fay supposed that there were two fluids : the one de- 
veloped by the friction of the glass he called vitreous, which 
answers to the positive electricity of Franklin, and the other, 
developed by the friction of the wax, he called resinous, which 
corresponds with the negative electricity of Franklin. Each 




Electricity. — Gold Leaf Electrometer. 75 

fluid repels itself, and attracts the other. It follows from 
tliis theory, that substances electrified by the same fluid repel, 
and those electrified by the opposite fluids attract, each other, 
and friction only tends to separate them. 

The existence of the two fluids may be shown Fig. 30. 
by the Gold Leaf Electrometer ,* (Fig. 30,) which 
consists of two strips of gold leaf suspended by a 
brass cap and wire, in a glass cylinder. When 
electrified with either kind of electricity, the leaves 
diverge. * 

But if, when the leaves diverge with negative 
electricity, a substance excited positively be brought 
near, the leaves will collapse. 

Exp. Bring excited sealing-wax in contact with the brass knob a, 
the leaves will diverge with negative electricity. Place now,^xcited 
glass upon the knob, and the leaves will come together, because the 
positive fluid restores the equilibrium. If pith balls be suspended by a 
wire tr thread, similar effects may be produced. 

Some substances, such as glass and resin, retain the elec- 
tricity upon their surfaces when excited, and are hence called 
non-conductors of electricity. 

Other substances, as the metals, do not retain electricity 
upon their surfaces, unless they are surrounded by non-con*- 
ductors, but convey it away, or oppose no barriers to the 
union of the two fluids ; such bodies are called conductors of 
electricity. The metals are all conductors ; dry air, glass, 
sulphur, and resins, are non-conductors ; water, damp wood, 
moist air, alcohol, and some oils, are imperfect conductors. 
The non-conductors are called insulators. 

Some substances exhibit signs of electricity when heated, 
Kuch as tourmalin, topaz, diamond, beryl. 

Electrical Machine. The instrument by which the phe- 
nomena of common electricity may be best exhibited, is the 
electrical machinei (Fig. 31,) which consists of a cylinder, or 
piate of glass G, revolving on an axis, and subjected to the 
friction of a rubber R of leather or silk, upon which is spread 
a thin coat of amalgam, composed of tin and mercury, 

* HXexroov and jhetqov, a measurer of electricity. 

i In the absence of an electrical machine, many experiments may be 
performed with a rod of glass, or sealing-wax, two inches in diameter, 
and rubbed with a silk handkerchief 



76 



Electrical Machine. 
Fig. 31. 




insulated by a glass pillar, and communicating with the ground 
by a brass chain, C. Attached to the machine is a cylindrical 
metallic conductor, P, which is also insulated by a glass pillar. 
When the machine is in operation, vitreous electricity 
flows from the rubber and glass, by means of fine points, to 
the prime conductor, P, and resinous electricity passes in an 
opposite direction. If the hand be placed upon the con- 
ductor, currents of electricity will pass in opposite directions, 
the vitreous passing into the body from P, and the resinous 
down the chain C to the ground. But if the hand be held 
at a little distance from the conductor, a spark will dart 
through the air, and cause a prickling sensation, accompanied 
by a slight report, with light and heat. The sound is pro- 
duced by the collapse of the air, as the fluid forces a passage 
through it; and the light and heat are supposed to result from 
the sudden condensation of the air, as in the fire syringe. 

Induction. If an insulated body be brought near the prime 
conductor, it will manifest signs of electricity opposite to 
that of the conductor, on the side nearest the conductor, and 
similar to the conductor on the other side, while the centre 
of the body will be neutral." The electricity, in this case, is 
induced by the presence of the electrified conductor ; and 



V \ 



Electricity. — Induction — Theory. 77 

the process is called induction. Several insulated conductors 
placed contiguous, will exhibit the same phenomena if a 
communication be made between the last and the ground. 

Thus, (Fig. 32,) Fig. 33. 

let A represent the 12 3 4- 5 

positive conductor |k A IV J 

of an electric ma- _^J!v> #| 7> ]H 1 c 

chine, b and c in- ^\aT-- * <• il^. ^ £ 
sulated conductors, |, K 

with a chain pass- M*. -Js 

ing to the ground. 

The conductor b will be electrified by induction, as will be 
indicated by the attached balls. Thus 1, being positive, will 
attract the balls 2, which are rendered negative by inchiction. 
The balls 3 are also rendered positive, 4 negative, and 5 
positive, while the centres b c will remain neutral. 

Theory. The phenomena of induction has led to the 
true theory of attraction and repulsion. The reason why an 
excited body attracts another is, that it induces in it an 
opposite electrical state. Induction is therefore an essential 
function, both in the development and continuance of elec- 
trical currents, and consists in a polarized state of the 
particles, or positive and negative points, induced by the 
presence of an electrified body. 

Application of the Theory. According to this theory, an 
excited body attracts light substances, because it induces in 
them an opposite state of electricity. 

1. On moving the hand towards the prime conductor, it is 
electrified negatively by induction ; when a spark is received, 
the equilibrium is restored. 

2. When a cloud, positively or negatively electrified, 
passes over a tower, or a tree, it induces an opposite state in 
them, and a stroke of lightning follows in consequence of the 
attraction between the two accumulated fluids; hence the 
utility of lightning-rods to form a communication between 
the clouds and the ground. 

3. The action of the Ley den Jar is due to induction Tt 
consists of a glass jar, lined on the inner and outer surfaces, 
pave a few inches near the mouth, with tin foil. Through the 
•topper, made of dry wood or sealing-wax, a brass rod com- 



78 



Electrometers. 



municates with the inner surface. When positive electricity 
is applied to the inside, it drives off the same fluid on the 
outer surface, and induces the negative fluid. These fluids 
exert a strong mutual attraction upon each other, through 
the glass, and enable both to accumulate in larger quantities 
than they would do on separate conductors. When a com- 
munication is made between the inner and outer surfaces, 
the equilibrium is suddenly restored, accompanied by a 
sharp report. When several jars are connected by their 
outer surfaces, and also by their inner surfaces, they consti- 
tute an electrical battery. 

4. The action of the Electrophorus 
(bearer of electricity) (Fig. 33) de- 
pends upon the same principle. It may 
be constructed by pouring melted resin 
into the cover of a firkin, taking care, 
when it cools, to render the surface even. 
Adapt to this a circular piece of board 
covered with tin foil, and fix a glass rod 
in the centre for a handle. This instru- 
ment may be used instead of the machine for charging Ley- 
den Jars. 

Electrometers, or Electroscopes. These are instruments for 
detecting the presence of electricity, as in the Gold Leaf 
Electrometer, (page 75,) or for determining the degree of its 
tension, or attracting and repelling power. For this last 
purpose, the Balance Electrometer is used. 





Thus A (Fig. 34) is a Ley den jar, which may be <*»n 



Laws of the Accumulation of the Electric Fluid. 79 

nected with the prime conductor of an electric machine ; B, 
a brass ball connected with D, E ; C, another ball, with a 
chain, G, connecting it with the table or the outside of the jar ; 
D, a brass rod balanced at the centre, and insulated by the glass 
post H ; E is a ring which may be placed at any distance 
from F, bringing the ball in contact with B. If, now, the jar 
be positively electrified, the ball on the end of E will be re- 
pelled, C will be electrified negatively by induction, and 
there will be a powerful attraction between C and 'the ball 
on the end of D, which will bring them together, and the 
equilibrium will be restored. The force of attraction will be 
measured by the distance between the balls and the weight 
applied at E. With a powerful electrical battery, successive 
vibrations may be produced in the beam, and a bright spark 
and loud report produced at each contact of the balls. 

Laws of the Accumulation of the Electric Fluid. 

1. Free electricity is always accumulated upon the surface 
of an insulated conductor, and does not penetrate its sub- 
stance ; hence the quantity does not depend upon the quantity 
of matter in the conductor, but upon the extent of surface. 

2. The mode in which electricity is distributed over the 
surface of conductors, depends upon their form. On a sphere, 
it forms a uniform stratum. On an ellipsoid, the stratum is 
thickest on the extremities of the longer axis, and, as these 
extremities approach to the form of points, the accumulation 
increases till the tension becomes so great, that it flows off 
into the atmosphere ; hence electricity cannot be retained on 
a conductor which has points attached to it. 

3. This tendency to escape is due to the repulsion of its 
particles. 

4. Coulomb proved by his Torsion Electrometer, that the 
repulsion of two bodies similarly electrified, and the attraction 
of two oppositely electrified, varies inversely, as the square 
of the distance between them. 

Sect. 2. Voltaic Electricity, or Galvanism. 

History. In the year 1791, Galvani, an Italian Professor 
of Anatomy at Bologna, discovered that if a silver probe were 
made to touch the crural nerve of a recently killed frog, and 
a strip of zinc the muscle, violent contractions would be pro- 
duced at each contact of the two metals — the same effect as 



80 Simple Voltaic Circles. 

is produced by an electric spark. Hence he concluded thai 
the phenomena were due to electricity, generated by the 
animal system. Some years after, Prof. Volta, of Pavia, dis- 
covered that the animal system was not necessary to the de- 
velopment of this kind of electricity, which he proved by the 
construction of a pile of insulated plates, of different metals, 
called tiie Voltaic pile. This discovery has given to this form 
of exciting electricity the epithet voltaic. 

But the identity of the agent concerned in galvanism, and 
of that in the common electrical machine, is now a matter of 
demonstration. Magnetism has been supposed to be due to 
the same agent, and also chemical affinity. But it is more 
in accordance with all the phenomena to suppose that those 
agents are not identical, but, in many respects, distinct forces. 
" Galvanism," according to Dr. Hafe, " is light, heat, and 
electricity, combined." 

I. Simple Voltaic Circles. Exp. Place a piece of zinc 
upon the tongue, and a piece of silver under it : whenever the 
projecting edges of these metals are brought into contact, a 
peculiar sensation will be perceived, and, if the plates are 
large enough, a flash of light. This effect is not due to elec- 
tricity generated by the animal system, but to that developed 
in the metals ; for if the same plates, -,.„. gr 

or larger plates, be placed in water, s~~*\ ? ' /^""N. 
(Fig. 35,) and the connection made, / +Sjr — Lpr \ 
electricity will be excited; feeble in- / jp~l : — : S> j 
deed, but in sufficient quantities to be I I N^| , / 
detected by a proper apparatus. If, ^\ fc jj ir j /# 
however, a few drops of sulphuric or <^N^ ^^ 

nitric acid be added to the water, and /~^\ 

the ends of the plates C and Z brought 
into contact directly, or by means of wires soldered to the 
plates, bubbles of hydrogen gas will rise from the surface of 
the copper plate C, and electricity will be developed in larger 
quantities. The currents will continue to circulate from one 
plate to the other, as long as the wires are kept in contact, 
but will cease when they are separated. This is a case of a 
simple voltaic circle. The direction of the positive current 
is indicated by the position of the arrows. When the wires 
are in contact, the circuit is said to be closed, and a current 
of positive electricity flows through the water from the zinc 
plate Z to the copper C, and from the copper along the con- 



Compound Voltaic Circles. 



81 



ducting wires to the zinc. A current of negative electricity, 
on the theory of two fluids, passes in an opposite direction. 
When the wires are separated, the circuit is said to be broken 

The contact may be made above the water, or in it, or the 
plates may touch each other throughout, or be soldered to- 
gether ; in either case electricity will be excited ; but if one 
plate is out of the liquid, no currents can be produced. 

A simple voltaic circle may be formed of one metal and 
two liquids, provided a stronger chemical action is induced on 
one side of the plate, than on the other. Simple voltaic cir- 
cles may also be formed of various materials ; but, generally, 
they consist of one perfect and two imperfect conductors 
of electricity, cr of two perfect and one imperfect conductors. 

Metals and prepared charcoal are perfect, water and 
a'queous solutions imperfect conductors. But, whatever be 
the construction, chemical action seems absolutely necessary 
to the development of voltaic currents. 

The most common and convenient form 
of the simple battery, is that of two cyl- 
inders of copper, C, (Fig. 36,) the one 
within the other, separated about one 
inch, with a bottom soldered on, so as to 
contain the exciting liquid, a, between 
them, and a cylinder of zinc, Z, placed 
oetween the two cylinders of copper, and insulated by ivory 
handles The two plates are furnished with wires, terminated 
by the cups b b, which contain a globule of mercury. The 
connection is made by means of x&Oes dipped into the mercury 
in the cups. Or, the copper and zinc may be coiled around 
each other, so that each sirfface of zinc may be opposed to 
one of copper, but separated from it by a small interval. 
By thus exposing a large surface of zinc to a similar sur- 
face of copper, Dr. Hare was enabled to melt the most 
refractory metals, and from this circumstance gave it the 
name of Calorimotor, 

II. Compound Voltaic Circles. Compound circles consist 
of a series of simple circles, for the purpose of increasing 
the intensity of voltaic currents. The first combination of 
Ibis kind was made by Volta, and is called the voltaic pile. 

4* 




82 



Compound Voltaic Circles. 




1. This pile consists of zinc a*nd copper plates, 
(Fig. 37,) placed alternately one above another, 
with strips of woollen cloth moistened with salt 
water between each pair. By connecting the top 
and bottom plates, currents of electricity will be 
set in motion. 

2. But other forms of voltaic circles are now 
in use. The most convenient is that invented 
'by Wollaston. It consists of any convenient 
number of zinc and copper plates, so arranged, 

that each zinc plate is surrounded by two of copper. 

A (Fig. 38) is a trough to contain the exciting liquid ; B 
a case passing around the plates, and connected by chains to 
the windlass C, by means of which the plates can be lowered 
into the liquid, or raised to any position required.* EE are 
small hand-vices attached to the poles. The zinc plates are 
confined in copper cases, insulated by wood at each end. 
The copper cases are separated ^ of an inch, by pasteboard, 
which, with the wood, is saturated by oil and wax. The 
connection between the zinc and copper plates is made by 
strips of copper soldered to the zinc of one pair, and to the 
copper of the adjacent pair ; by this construction, the power 
of the battery is increased nearly one half. 




As each zinc plate is connected to the adjacent copper 
plate, the currents are urged along from one to the other, in 
opposite directions, till they meet at the poles. 

The size and number of plates ma^foe varied at pleasure. 
The largest battery ever constructed i^iat of Mr. Children, 



* In some batteries, the plates are stationary 
and lowered. This is the most convenient 
large batteries. 



rand the trough is raised 
istruction, especially in 



Grove's Bail 



cry. 



83 



lie plates of which were & ft. long and 2 ft. 8 inches broad. 
The most convenient size is 4 inches by 6. A battery con- 
taining 200 or 300 plates, and thrown into vigorous action, is 
rly as powerful as one much larger.* The battery of 
Dr. Hare is called a Defiagrator, from its surprising power 
of burning the metals. 

The direction of the currents in this apparatus is the same 
as in the simple circles : positive electricity passes from the 
zinc through the liquid to the copper plates, and is given off 
at the copper pole of the battery, while negative electricity 
takes the opposite direction, and appears at the zinc or 
tive pole. 

During the action of the battery, all the hydrogen evolved 
in the process is given off at the surface of the copper, and 
the weight of the hydrogen during any given time, and that 
of the zinc dissolved, will be as 1 to 32.3, which is the ratio 
of their chemical equivalents. This shows the close con- 
nection between electricity, thus excited, and chemical 
affinity. 

F£g. 39. 




2. Grove's Battery. — One of the most powerful as well as 
economical batteries now in use is the one constructed by 
Prof. Grove. It consists of a series of platinum and amal- 
gamated zinc plates arranged in the following manner. The 
zinc plates are cast in the form of hollow cylinders, a, a, 



* In experimenting with the battery, the plates should not be im- 
mersed in the liquid but a few minutes at a time; by raising and lower- 
ing them for each experiment, their vigorous action will be kept up much 
longer; or the troughs maybe so constructed, that, by a partial revolu- 
tion, the exciting liquid may be withdrawn from the plates, or thrown 
Open them at pleasure, 



84 Galvanic Batteries^ 

(Fig. 39.) with a projection, &, b, about two inches in length, 
to the er.d of which strips of platinum foil are soldered. 
Within the zinc cylinders small earthen cups are placed. 
These are then put in half-pint glass tumblers ff; the zinc 
in one tumbler and the platinum foil, attached to its end, in 
the earthen cup of the next plate. The zinc is the negative, 
and the platinum the positive pole or electrode. 

To charge the battery, sulphuric acid, diluted with 5 or 6 
parts water, is put into the tumblers to act upon the zine 5 and 
strong nitric acid into the earthen cups in contact with the 
platinum foil. 

When the poles are united, positive electricity is generated 
in the zinc plate at the negative end of the battery, and passes, 
with the hydrogen of the decomposed water, into the porous 
cup, to the platinum plate, as indicated by the arrows. The 
nitric acid is decomposed by the current, the hydrogen 
unites with its oxygen, and the binoxide of nitrogen escapes 
into the air. The current then passes to the zinc plate, 
thence from zinc to platinum, through the conducting fluids, 
to the platinum or positive pole. The negative current 
passes in the opposite direction, commencing at the platinum 
plate and passing to the negative pole. 20 or 25 cups will 
produce effects fully equal to one hundred or more of zinc 
and copper plates. The intensity of the action may be kept 
up for a very long time ; hence such batteries are called 
Sustaining Batteries. 

Smee's Battery is, however, the most simple, and the most 
easily managed o." any which have yet been noticed. It con- 
sists of silver and ama^mated zinc plates, (Fig. 40.)* 

The silver plate is cove^erl with platinum, in fine division 
called platinum black, and is piacfd between two zinc plates, 
b b (Fig. 40) and secured by a clamp. The battery is then 
charged by placing it in a half-pint tumbler containing di- 
luted sulphuric acid. The action commences whenever the 
poles s % are in contact, and ceases when they are separated. 
This battery is remarkable for affording a constant current 
of electricity for days and weeks together ; hence its use in 
electro-metallurgy. It is distinguished for the quantity of elec. 
tricity it is capable of generating, but is surpassed by most 
c2?a.rH for intensity of action. By increasing the number of 
* Manufactured by B. Pike & Son^ N. Y. 



Theories of Galvanism. 



85 



Fig. 10. 




plates, however, sufficient power is generated for most ex- 
periments. For experiments in electro-magnetism, it is far 
preferable to any other. Instead of the silver plate, one of 
lead covered with silver, and then with platinum black, is 
said to work better than a thin plate of silver. 

Theories of Galvanism. 

On this subject there are three theories: 1. The first 
originated with Volta, who conceived that electric currents 
are set in motion, and kept up, solely by contact of the dif- 
ferent metals. He regarded the interposed solution merely 
as a conductor to convey the electricity from one point to 
another. 

2. The second theory was proposed by Dr. Wollaston, 
who supposed that chemical action was the sole cause of 
exciting and continuing the voltaic currents ; and the fact 
that no sensible effects are produced by a combination of 
conductors, which do not act chemically upon each other, is 
the strongest proof of its truth : even in the voltaic pile, the 
energy of the action depends upon the oxidation of the zinc. 



86 Laws of the Action of Voltaic Circles. 

3. The third theory was suggested by Sir H. Davy, and is 
intermediate between the two preceding. He supposed that 
the electric equilibrium was disturbed by contact of the 
metals, and the electric currents kept up by chemical action. 

The theory of Wollaston is now generally embraced. 

Laws of the Action of Voltaic Circles, 

Electricians distinguish between quantity and intensity in 
Galvanism, as in ordinary electricity. 

Quantity refers to the amount of the electric fluid set in 
motion ; tension, or intensity \ to the energy or effort with 
which a current is impelled. Common electricity has great 
tension ; voltaic, great quantity, — and this is the principal 
difference between them. 

1. In the broken circuit, there is a strain to establish an 
electric current, because without this, oxidation cannot take 
place. There exists between the exciting fluid and the zinc, 
a desire, as it were, for chemical action, which cannot be 
gratified until, by closing the circuit, a door is opened for the 
escape and circulation of electricity. This strain or tension 
is great, according as the affinity between the exciting fluid 
and the zinc is great. Currents of high tension are urged 
forward with greater impetuosity than feeble ones, and hence 
they more readily overcome obstacles to their passage. 

2. Currents from a single pair of plates have not a high 
tension; but if the plates are large, a great quantity of elec- 
tricity is set in motion. 

The condition which causes a high tension is an extended 
liquid conductor, along the whole line of which successive 
pairs of plates are arranged ; each acted upon chemically by 
the exciting liquid, and urging on the current in the same 
direction. But the quantity in this case may not be great; 
for, although its tension is increased by the force which each 
plate gives to the current as it passes, the quantity which 
passes along the wire, according to Faraday, is exactly equal 
to that which passes through one of the cells in which the 
plates are immersed. 

3. The energy of voltaic currents is measured either by 
their power of deflecting a magnetic needle, or by that of 
chimicaJ, decomposition. The deflection of the needle depends 



Electricity. — Effects of Galvanism. 87 

upon quantity ; hence a single pair of plates will deflect the 
needle more than a number of small ones combined ; but de- 
composition depends upon quantity and intensity together. 
The decomposing power of the battery, however, does not 
increase in the ratio of the number of plates, but as the 
square root of the number, so that, when the number varies 
as 1 to 4, the decomposing power is as 1 to 2. 

The deflecting power of a single pair of plates varies in- 
versely as the square root of the distance between them. 
Thus, if a plate of zinc be placed at one, four, and nine 
inches from a plate of copper, the deflecting powers will be 
in the ratio of 3, 2, 1. 

4. The velocity of common electricity through perfect con- 
ductors, is surpassed only by that of light, being, according to 
Wheatstone's Experiments, about 5^88,000 miles per second. 
From some experiments, it is infered that the velocity of 
voltaic electricity is somewhat less. Hence this agent has 
been employed to communicate intelligence from one place 
to another. The Electro-Magnetic Telegraph, by which this 
is effected, depends upon the velocity of electricity and its 
power to impart magnetism to soft iron. 

Effects of Galvanism. 

I. The effects of common and voltaic electricity have many 
points of resemblance. 

1. If a zinc and copper plate be immersed in dilute nitric 
acid, and the wire attached to the zinc plate be made to 
touch a gold leaf electrometer, the leaves will diverge with 
negative electricity, and if the wire of the copper plate be 
applied, it will indicate positive electricity. This effect is 
much greater when a battery of several pairs of plates is 
employed. It appears to be due to the disturbed equilibrium 
in the zinc plate ; the chemical relation of which to the acid 
renders the metal positive, at the expense of the attached wire, 
while the copper plate, induced by the contiguous zinc, be- 
comes negative) at the expense of its wire, which becomes 
positive. 

2. A Ley den jar may be charged from either wire of an 
unbroken circuit, provided a large quantity of electricity be 
developedj connected with high tension. This effect depends 
upon the number of plates and the energ^of the action. 

3. Voltaic, like common electricity, passes through the 



88 Effects of Galvanism. 

air, and other non-conductors, in the form of sparks, accom 
panied with a report, and the development of light and heat. 
Hence it will inflame gunpowder, phosphorus, hydrogen and 
oxygen, and other inflammable substances. 

4. Its tension, however, is so feeble, compared with com- 
mon electricity, that it has, according to Mr. Children, a very 
small striking distance; i. e., the space of air through which 
the spark will pass is comparatively small. With a battery 
of 1250 pairs of four-inch plates, he found the striking dis- 
tance to be -^ of an inch. If the air be rarefied, the distance 
will be increased, and diminished by condensation. 

5. The effect of voltaic electricity upon the animal sys 
tern is similar to that of common electricity. 

6. Both kinds also deflect the magnetic needle, and pro- 
duce chemical decomposition. 

II. One of the most surprising effects of voltaic currents 

is their 'power of igniting the metals. 

Exp. Attach to each pole of the battery strips of metallic leaves, 
and bring them in contact ; the metals will burn with the most vivid 
scintillations. (See Fig. 38.) 

The color of the light varies in different metals. Gold 
leaf burns with a white light, tinged with' blue, and yields 
a dark brown oxide. Silver emits an emerald-green light, 
of great brilliancy ; copper, a bluish-white light, with red 
sparks; lead, a beautiful purple ; and zinc, a brilliant white 
light, tinged with blue and red. If the communication be 
made with charcoal points, (that from the box-wood is the 
best,) the light is equal, if not superior, in intensity, to that 
emitted during the combustion of phosphorus in oxygen gas, 
and the heat is sufficient, it is said, to partially fuse the car- 
bon, a substance which is fusible by no other means of pro- 
ducing heat* 

Theory. The heating power seems to be due, for the 
most part, to the quantity of electricity developed ; hence, for 
melting wires, a calorimotor is preferable to a compound hat- 
iery. The heat is supposed to arise from the difficulty with 
which the electric currents pass along the conductors ; but 

* On examining the points after they have been subjected to tlra 
action of. a powerful battery, one will present a conical appearance, like 
the head of a pin, th# other a corresponding cavity. The carbon thus 
transposed has been supposed to be partially melted; and recent exper- 
iments seem to confirm this view. 



Chemical Ejects oj Galvanism. 89 

as the substances are good conductors, the effect will take 
place onlv when the quantity of electricity transmitted, is out 
of proportion to the extent cf surface over whicH it has 
to pass. 

As heat and light are produced in vacua, under water, or 
in gases which do not contain combustible matter, these phe- 
nomena cannot be attributed to combustion, but to the pro- 
duction of light and heat by the electric fluid itself. The 
effects of common electricity from the electric machine, 
and in the case of lightning, are so similar to those above 
described, that there can be no doubt of the identity of the 
agents concerned in their production. 

III. Chemical Effects of Galvanism. The phenomena 
which accompany chemical combinations are similar to those 
produced by voltaic electricity. But the agency of voltaic 
currents to effect the decomposition of chemical compounds 
is a most important and useful discovery, which was first made 
by Carlisle and Nicholson. 

1. The first substance decomposed by the gal- 
vanic battery was water. The water for decom- 
position is put into a small vessel, a, (Fig. 41.) 
The tubes h o, after being filled with water, are 
inverted in the vessel, passing through holes in the 
stopper ; n and p are platinum wires passing 
through the sides of the vessel into the open ends 
of the tubes. When the poles of the battery are 
connected with the. wires, the positive with p, and 
the negative with ?i, hydrogen gas is disengaged 
at the negative, and oxygen at the positive wire. 
The two gases will rise up in the tubes in small bubbles, and 
displace the water. By measuring the gases, it will be found 
that there will be exactly two measures of hydrogen in the 
tube h to one of oxygen in the tube o. If the gases are col- 
lected in the same tube and exploded in the eudiometer, they 
will entirely disappear, and water will again be formed. By 
this means, the composition of water, both by analysis and 
synthesis, is accurately ascertained. 

This important discovery led to similar trials upon other 
substances. Other compounds, such as acids, salts, and alka- 




90 Chemical Effects of Galvanism. 

fies, were subjected to the agency of galvanism, and all were 
decomposed — one of their elements appearing at the positive, 
the other at the negative pole. In these decompositions, it 
was found that the same kind of body always went to the 
same pole. The metals, inflammable substances in general, 
alkalies, earths, and the oxides of the common metals, were 
uniformly found at the negative wire, while oxygen, chlorine, 
and the acids, were found at the positive pole. This led to 
a division of substances into Electro-positive, and Electro- 
negative- — a distinction,however, which is not found, by later 
experiments, to accord with facts. 

2. The transfer of chemical substances from one vessel to 
another was noticed by Sir H. Davy. This transfer may be 
shown by two wine-glasses, (Fig. 42.) 

Put a solution of sulphate of soda into one, Fig. 42. 

n, and distilled water into the other, p ; then 
connect them with moistened amianthus or 
cotton thread. If, now, the negative pole of 
the battery is connected with n, and the pos- 
itive with p, the acid will pass over into the cup p containing 
the distilled water — if the poles are reversed, the alkali will 
pass over into this cup. If, instead of distilled water, infusion 
of purple cabbage be used, the presence of the acid will be 
detected by the red color which it will give to the infusion, 
and that of the alkali by its changing the infusion to green.* 

But the effect in this experiment, and in those where three 
vessels are used, (the middle one of which, although contain- 
ing a very delicate test of the presence of an acid or of an 
alkali, will suffer them to pass through it without detection,) 
can be accounted for on the principle that a part of the salt 
passes over into the cup by capillary attraction; as it has 



* A very simple apparatus for showing the changes of 
color when salts in solution are subjected to galvanic 
action, is shown in Fig. 43, which consists of a glass tube, 
bent in the form of the letter U. Fill both legs with a 
neutral salt colored with the infusion of purple cabbage ; 
on immersing the poles p and n, the color may be trans- 
ferred from one leg to the other as often as the poles are 
changed. 





Chemical Effects of Galvanism. 91 

been proved by Faraday that decomposition never takes 
place unless the electric fluid actually passes through the sub- 
stance. 

It was in pursuing these researches that Davy mad* his 
great discovery of the decomposition of the alkalies and 
earths, which, until that time, had been considered simple 
bodies. 

Theory. The theory of decomposition, proposed by Davy, 
was this : He conceived that the poles of the battery were 
centres of attraction to one element of the compound, and of 
repulsion to the other ; hence, when the two poles were im- 
mersed in water, the oxygen of the water was attracted by 
the positive, and repelled by the negative pole, while the hy- 
drogen was repelled by the positive and attracted by the neg- 
ative pole. The elements, thus acted upon by four forces, 
»vere separated, and made to appear at their respective poles. 

But this theory does not account for all the phenomena, 
[f it were true, we should expect decomposition to be effected 
by one pole alone, as it exerts the attractive and repellent 
influence ; but this is never the case. 

Mr. Faraday has lately revised this part of the subject, and 
not only added much that is new, but shown that many prin- 
ciples, especially the above theory, are erroneous. 

He contends that the poles have no attractive or repulsive 
tendency, but simply afford a path for the voltaic currents 
to enter the liquid. Instead of poles, he calls them elec- 
trodes* which means the way or door for electric currents, 
and may be air, water, metal, or any other substance capable 
of conducting the currents to and from the substance to be 
decomposed. The point where the positive current enters 
the liquid, he calls the anode,i and that where it quits it, the 
cathode. J 

When a compound is decomposed by galvanism, it is said 
l<* be elcctrolyzed,§ and substances capable of decomposition 
»re called electrolytes; the elements of an electrolyte are 



* From rJ.sy.TQov and 6$oc:, a way. 

t From ura, upwards, and odos, the way in which the sun rises 

X From xara, doicni rd/r, t-he way in which the sun sets. 

§ From jjAfixTfov and • ,.. jo unloose or set free. 



92 Results of Faraday's Investigations, 

called ions.* Anio?is are the ions which appear at the anode 
cations, those that appear at the cathode. The anions are 
the electro-negative substances, such as oxygen, chlorine, 
acids, etc. ; the cations, the electro-positive, such as hydro- 
gen, alkalies, metals, etc. 

The following are the principal results of Faraday's inves- 
t'gations : — 

1. All compounds, contrary to what has been hitherto 
supposed, are not electrolytes; that is, are not directly de- 
composable by the voltaic currents. But many bodies may 
be decomposed by secondary action. Thus water is directly 
decomposed by an electric current ; but nitric acid is decom- 
posed by secondary action — the decomposition of the water 
contained in it, aids the decomposition of the acid. Very 
numerous secondary actions are produced in this way, because 
the disunited elements, separated by direct action, are pre- 
sented in their nascent form, which is peculiarly favorable to 
chemical action. 

2. Most of the salts or secondary compounds are resolva- 
ble into acid and oxide ; but in the binary compounds, such 
as acids and oxides, the ratio of combination has an influence 
which has been hitherto overlooked. No two elements ap- 
pear capable of forming more than one electrolyte. The 
proto-chloride of tin is readily decomposed, but the by-chlo- 
ride is not. Hence substances which consist of a single 
equivalent of one element, and two or more of another, are 
not electrolytes, that is, are not decomposed directly by 
electricity. 

3. Most of the simple substances are ions, that is, capable 
of forming compounds decomposable by galvanism. 

4. A single ion, by itself, has no tendency to pass to either 
of the electrodes, that is, it is indifferent to the voltaic cur- 
rents. 

5. There is no such thing as a transfer of the ions, in the 
sense supposed by Davy. In order tliat the elements of water 
should appear at the two electrodes, there must be a row of 
particles between them. 

6. The air, or the surface of water, may constitute an elec- 
trode, as well as metals. 

7. Electro-chemical decomposition cannot occur unless a 
current of electricity actually passes through the compound , 

* From iov, going, neuter participle of the verb to go. 



Theory of Electro-Chemical Decomposition. 93 

that is, the compound must be a conductor of electricity 
On this principle many substances, by change of state, resist 
decomposition. Water is easily decomposed, but ice is not ; 
many solid substances, also, are not electrolytes, because they 
are not conductors. Chemical compounds differ in the elec- 
trical force required for their decomposition ; some require 
but a feeble current, others a powerful one. 

8. The conduction of the electric currents in the cells of a 
battery depends upon decomposition. If the zinc or the cop- 
per be attacked chemically by a substance which is simple, or 
a non-conductor, ho currents can be set in motion. 

9. Electro-chemical decomposition is perfectly definite; 
that is, in the voltaic circle 32.3 parts of zinc are dissolved 
during the evolution of one part of hydrogen. This is in the 
ratio of their chemical equivalents. The same is true of all 
electrolytes. Hence Mr. Faraday has given to the quantities 
of electricity, requisite to effect the decomposition of various 
substances, the name of electro-chemical equivalents. This is 
a new and important discovery, and illustrates the close 
connection between chemical affinity and electricity. Hence, 
in order to estimate the quantity of electricity circulating in 
a voltaic apparatus, it is only necessary to collect the gas 
evolved from the acidulated water during any given time. 

Theory of Electro-Chemical Decomposition. W.e have al- 
ready noticed the theory cf Davy, which supposes that all 
substances are in one of two states of electricity, and that the 
poles have an attractive and repulsive force; but Mr. Faraday 
has shown that this theory cannot be true. All substances 
are indifferent when by themselves, but assume one of the 
two states when brought in contact. Only one substance is 
ys negative — Gxygen ; and but one always posi- 
tive — potassium : between these extremes, they may be made 
to assume either positive or negative states. To account for 
the decomposition of water, we must conceive of a line of 
particles between the two electrodes, along which the current 
passes. When a particle of oxygen is evolved at the positive 
electrode, its hydrogen is not transferred at once to the op- 
posite electrode, but unites with the oxygen of the contiguous 
particle of water, on the side towards which the positive 
current is moving ; then it passes to the next, and so on, until 



94 Magnetic Effects of Electricity. 

it arrives at the pole. A similar row of particles of oxygen 
start from the negative electrode at the same moment, and 
combine successively with the particles of hydrogen as they 
pass them on their way to the positive pole or electrode.* I 
is supposed that other compounds are decomposed by a 
similar process. 

Magnetic Effects of Electricity, or Electro-Magnetism. ~~ 
History. It had been noticed for a long time that, when a 
ship, for example, was struck with lightning, the magnetic 
needle often had its poles destroyed or reversed, and that the 
iron often became magnetic. This led to the supposition, 
that electricity might be employed to communicate the mag- 
netic properties to iron or steel ; but no results of importance 
were obtained until the winter of 1819, when Prof. Oersted, 
of Copenhagen, made his famous discovery, which forms the 
basis of a new and very important branch of science. 

I. Influence of Voltaic Currents upon the Magnetic Nee- 
dle. The discovery made by Oersted was, that the me- 
tallic wire, or any part of a closed voltaic circle, causes a 
magnetic needle, when brought near it, to deviate from its 
natural position, and assume positions depending upon the 
relative position of the needle and the wire. 

Thus, suppose a magnetic needle freely suspended with its 
poles pointing north and south. (See fig. 41.) 

1. If, now, a positive current pass from north to south in 
the same plane with the needle, but a little above it, the north 
pole will turn to the east, and the south pole to the west. 

2. If the current pass under the needle, the north pole 
moves west, and the south east. 

3. If the current pass on the west side of the needle, and 
in the same horizontal plane, the magnet will have a tendency 
to move in a vertical direction, the north pole being elevated, 
and the south depressed. 

4. If the current pass on the east side, the north pole is 
depressed, and the south elevated. 

5. If the current flow from south to north, the needle will 
move in opposite directions. 

* The quantity of electricity sufficient to decompose a single grain 
of water would be equal to a powerful flash of lightning. 



Magnetic Effects of Electricity. 95 

The deflection is rarely 45°, in consequence of the mag- 
netism of the earth ; but if that force is counteracted, as it 
may be, by suspending two magnets near each other, of equai 
power, with their poles reversed, the declination will be 90° ; 
hence the tendency of a magnetic needle is to stand at right 
angles to an electric current. 

6. If the wire be placed in a plane, perpendicular to the 
one in which the magnet moves, and the positive current 
ascends or descends to the centre of the needle, no action 
will take place ; but if it be moved towards the north or south 
poles, they will be attracted or repelled. Hence the plane in 
which a needle moves is ahoays perpendicular to that imchich 
the voltaic currents circulate. 

7. The phenomena of Electro-Dynamic action result 
wholly from electricity in motion, and depend upon quan- 
tity alone ; hence a simple circle of large plates is best fitted 
for exhibiting it* 

From the above facts it will be seen, that the magnetic 
needle may be employed, not only to ascertain the existence 
and direction of voltaic currents, but also to measure their 
torce. The instruments used for these purposes are called 

Galvanometers or Multipliers. As it is proved by experi- 
ment that every part of a wire in a closed circuit exerts an 
equal force upon the poles of a needle, if we can increase 
the number of points, the combined force will be greatly 
increased. This can be done by coiling the wire into the 
'brm of a circle or rectangle; each coil will exert its own 
force, independent of its neighbor, and the united force will 
depend upon the num- 
ber of coils. Thus (Fig. Flg * 44 * 
44) NP are the two ends ^ ^ 
of a copper wire bent in V. W ^ fp & 

the form of a rectangle, n 

in the centre of which, ^ Ir 2 ^ 
and in a plane perpendic- * 

ular to the plane of the 
wire, is placed a mag- 
netic needle. A gradu- 
ated circular plate meas- 

* The simple battery, Fig. 36, p. 81, is best fitted for experiments on 
this suljrct The exciting liquid should be a solution of sulphate of 
copper. 




96 



Electro-Magnetism, or 



ures the degree of declination, which indicates the quantity 
of electricity circulating along the wires. It will be seen, 
that if the positive current pass aboye the needle from north 
to south, that is, from P to a, and then pass around the south 
pole from A to B, there will be double the effect produced. 
By increasing the number of coils, the deflection of the 
needle will be much greater. This constitutes the Electro 
Magnetic Multiplier of Schweigger. 

If the directive power of the needle be destroyed, or if the 
currents are sufficiently powerful, the needle will stand at 
right angles to the direction of the currents. Then, if, at the 
moment it has attained this point, the currents be sent in an 
opposite direction, it will perform a revolution. Thus, by 
changing the direction of the currents, a needle may be made 
to revolve rapidly. 

If the magnet is fixed, and the rectangle suspended free to 
move, it will exhibit the same phenomena while the voltaic 
currents are passing around it. 

Fig. 45. 




Magnetic Effects of Electricity. 97 

The Revolving Rectangle is constructed on this principle. 
MM (Fig. 45) is a permanent horse-shoe magnet; C, a rec- 
tangular coil of copper wire, connected at each end to an 
axis, by which means it may be made to revolve ; ZP are two 
cups, to form a connection with the poles of a battery ; the 
wires bb are connected with the cups, and press on opposite 
sides of the cylindrical metallic pole-changer, which revolves 
between them. The pole-changer consists of two pieces of 
silver, with a small space between them ; one of these pieces 
is connected with one end of the wire of the rectangle, and 
the other piece with the other end ; a is an arch of brass to 
support the rectangle and the wires. If the two cups be 
connected with the battery, P with the positive, and Z with 
the negative pole, the positive current will pass along the 
wire b next to N, and from the wire to one side of the pole- 
changer, and thence several times around the rectangle to 
the wire b next to S. 

When the positive current is passing from P around this 
rectangle, one side is impelled towards one pole of the magnet, 
and the other towards the other pole. When the sides arrive 
in the plane of the poles, the force still continues to act, and 
they are forced by, and complete half a revolution, standing 
again at right angles to the poles of the magnet, the point at 
which they commenced their revolution : at this point the 
pole-changer sends the currents in opposite directions, and 
the revolution is continued. Reverse the current, by chang- 
ing the battery wires, and the rectangle will revolve in an 
opposite direction. 

II. The influence of voltaic currents on soft iron and steel 
was noticed by Davy and Arago about the same time. If an 
iron or steel needle be suspended in the galvanometer instead 
of the common needle, at right angles to the conducting 
wires, permanent magnetism will be communicated to the 
steel, and the iron will become powerfully magnetic, as long 
as the currents circulate, but will lose this property when 
the circuit is broken. Davy succeeded in producing a similar 
effect by a discharge from a common electric battery. 

1. This effect can be exhibited in the most satisfactory 

manner by coiling an insulated copper wire in the form of 

a helix, i \ (Fig. 46,) and connecting the two ends of the wire 

bb with the cups CZ, into which the poles of a battery may 

5 



98 



Electro-Magnetism. 



be inserted. Bars of soft iron or 
steel, placed in the coil, will become 
magnetized the instant the voltaic cur- 
rents circulate around the coil. If 
the positive current flows from Z 
around the helix, n will be the north 
pole, and s the south pole. If it flow 
from C, the poles will be reversed. 

2. If a bar of soft iron (Fig. 47) 
be wound with copper wire from c to 
a in one direction, and from a to d in 
an opposite direction, and currents of 
electricity passed around the bar, by 
connecting the wires b e 
with a voltaic battery, the 
bar will have three poles ; c 
and d will be similar poles, 
and a an opposite pole com- 
mon to the other two, as 
may be shown by bringing a 
magnetic needle near each. 
By changing the direction 
of the battery currents, the 
poles are reversed; hence 
the kind of pole depends upon the 
direction of the voltaic currents. 

3. Although soft iron does not re- 
tain its magnetism, yet its magnetic 
properties, while the voltaic currents 
are passing around it, are truly sur- 
prising. 

If a soft iron cylinder, two inches in 
diameter, and bent in the form of a 
horse-shoe magnet D, (Fig. 48,) be 
wound with copper wire, and the ends 
BC connected with the battery, it will 
be converted into a powerful magnet. 
On applying the armature A, it will 
sustain several hundred pounds. Mag- 
nets of this description may be made 
to sustain from 200 to 2000 lbs. It 
will be seen that the principle is the 
same as in the helix; and, as in the mul- 



Fig. 46. 




Fig. 47. 




Fig. 48. 




Magic Circle. 



99 




tipher, by increasing the number of coils, the magnet becomes 
more powerful, but the force does not increase directly as the 
number of coils ; for each additional coil is farther from the 
axis of the iron bar, and the power it exerts is inversely as 
the square of the distance from the axis. 

4. TJie Magic Circle, with two iron ar- 
matures, acts also on the same principle. 

r (Fig. 49) is a coil of insulated copper 
wire ; ab the two ends which may be con- 
nected with the battery. When the wires 
6 a are connected with the battery, and the 
two armatures are brought into contact, one 
of them passing through the ring, they adhere 
to each other very strongly, and, although 
they weigh less than § lb., they will sustain a weight of 56 lbs. 
without separation. The voltaic currents not only communi- 
cate magnetism to the iron and steel placed in the ring, but 
the helix itself becomes magnetic while transmitting the cur- 
rents, as is proved by its attracting iron filings. These and 
other facts, developed by voltaic currents, seem to prove the 
identity of the magnetic and electric fluids. 

5. Vibrating 3Iagic Circle. . MM (Fig. 50) is an electro- 
magnet, which may be used instead of a permanent magnet , 
c , a coil of coarse wire suspended from the post S ; one end of 
the wire a dips into the cup e, which is connected with the post 
S, and which also communicates with p; the other end of the 
wire d is connected with the other cup, which is insulated 
from the post S, 

and into which Fi »' 50 * 

also one of the 
poles of the 
battery may be 
immersed; con- 
nect the other 
pole of the bat- 
tery with p, and 
a current of 
electricity will 
pass along the 
post S to the 
cup e; as the 
wire a dips into 
it, the . current 




100 



Pages 's Revolving Magnet 



will pass down the wire b around the coil c, and then up the 
wire d to the other cup; as the currents circulate, the coil 
will be attracted to the pole of the magnet M; this will lift a, 
and break the circuit, and the coil will fall back beside the 
post S ; a will again be immersed in e, and the coil be again 
attracted upon M. Thus vibrations are produced as long as 
the currents of electricity circulate. 

6. Page's Revolving Magnet and Bell Engine. — By using 
an electro- magnet in connection with a permanent steel mag- 
net, or another electro-magnet, and reversing the currents by 
a pole changer, very rapid revolutions may be produced. 
The following is Page's revolving magnet, with a bell at- 
tached to mark the rapidity of the revolutions. 

Thus, N S (Fig. 51.)* repre- 
sents the north and south poles of a 
permanent horse-shoe magnet. A 
is a bundle of coarse iron wire, 
wound with copper wire, constitu- 
ting an electro-magnet, which is 
fitted to an axle S. By means of a 
pole changer, connected with the 
axle below the electro-magnet, the 
battery current may be made to pass 
in opposite directions as the magnet 
revolves upon its axle. By this 
means the polarity of the electro- 
magnet can be constantly changed. 
Suppose it stand at right angles to 
the permanent magnet, and is ren- 
dered magnetic by a current of 
.electricity, its south pole will be at- 
tracted to the north pole of the steel 
magnet, and its north pole to the 
south pole of the steel magnet. As 

it turns \ of a revolution, the pole r 

changer sends the current in the op- ~~ ■ "■ - 

posite direction, and changes its poles ; mutual repulsion now 
takes place, because similar poles are near each other, and it 
moves another quarter of a revolution by repulsion, and then 
another quarter 03^ attraction of opposite polarities. The mo. 
ment it has completed a half revolution, the poles are changed, 




Davis's Manual of Magnetism, p. 114, fig. 72. 



Yolta-Electric Induction. 101 

and it continues to revolve. To the axle is attached an endless 
screw, which acts upon a toothed wheel with a projecting pin 
for the purpose of raising the hammer of the bell at each 
revolution. If the wheel has 100 teeth, the magnet must re- 
volve 100 times to produce one revolution of the wheel, which 
is indicated by a stroke of the hammer against the bell. The 
velocity of the rotating magnet may be determined by no- 
ting the number of strokes in a minute, or in any given 
time. It has often made 100 revolutions in a second, or 6000 
in a minute ; and for each revolution of the magnet, its poles 
are changed twice or 12000 times a minute. For this effect 
the current must pass through some 20 feet of wire, and con- 
vert the inclosed bundle of iron wire into a magnet, twice at 
eacli revolution. Some idea may thus be formed of the 
rapidity with which this agent moves through conducting 
substances. On the above principles, and others yet to be 
developed, a variety of machines have been constructed. 
Many of them are beautifully figured and described in 
Davis's Manual of Magnetism. 

III. Volta- Electric Induction. The fact that an electri- 
cally-excited body induced electricity in other bodies brought 
near it, (page 78,) led Faraday to inquire whether electricity 
in motion would not have the same effect. This fact he soon 
established. 

If a copper wire be wound in the form of a helix, and the 
ends connected with a battery, and then another wire be 
wound around this, but insulated from it, aad the ends con- 
nected with a galvanometer, currents of electricity will be 
induced in the insulated wire, as often as the battery current 
is broken. All the effects of galvanism may be produced by 
the insulated wire. 

The phenomena of Volta- Electric Induction may be ex- 
hibited in the most satisfactory manner by the 

Separable Helices, (Fig. 52,) an apparatus very well fitted 
for illustration, for producing sparks, and imparting shocks 
of almost any degree of intensity. 

b (Fig. 52) is a hollow coil of coarse wire fixed upon a 
stand, Z ; one end of the wire is connected with the cup, and 



102 



Volta-Ekctric Induction. 

Fig. 53. 




i\\e other with the steal break-piece* which is fixed to the 
stand, by the side of the coil ; a is a coil of fine wire, which 
may be placed over the coil b ; d is a bundle of wires, which 
may be slipped into the copper case c, and placed in the cen- 
tre of the coil b. 

Fig. 53 represents this apparatus entire. The following 
are the principal facts which it is fitted to exhibit : — 

Exp. 1. Connect one pole of the battery with the cup on the left of c, 
(Fig. 52,) and move the. other pole along the break-piece ; vivid sparks 
will be produced at ^ack interruption. 

Exp. 2. Remove ::om the wires d the copper case c, and insert them 
gradually in the coil b while the currents are circulating, and the sparks 
on the break-piece will increase in brilliancy until the wires reach the 
bottom, when the greatest effect will be produced. 

Exp. 3. Place the coil a upon b, and let the currents circulate as before. 
If the handles ef, (Fig. 53,) which communicate with the extremities of 
the wire forming the coil a, be held in the hands, powerful shocks will be 
felt as the wire conveying the battery current passes across the break-piece, 
As the outer is insulated from the inner coil, the shocks do not proceed 
from the battery current, but from currents induced in the wire of the 
outer helix. Currents thus induced produce all the phenomena of the 
battery currents. 



* A break may consist of air, or any non-conductor, so connected with 
a conductor, that, when the wire conveying the voltaic current passes from 
the conductor to the non-conductor, the circuit may be broken ; and it is 
only at the moment of interrupting the battery current in the inner, that 
electricity is induced in the outer coil. 



Volta- Electric Induction, 

Fig. 53« 



103 




Exp. 4. A single wire* will increase the power of the shocks, and by 
increasing the number of wires, the sparks will increase in brilliancy, and 
the shocks will become more and more powerful. 

Exp. 5. If the copper case be placed upon the wires, the effect will be 
the same as when no wires are used. 



Fig. 54. 




The battery current which passes around the inner coil of 
wire is called the primary, and the induced current the 
secondary current. It is not necessary to this effect that one 
of the coils should surround the other, but may be placed 



* Fine wires answer a better purpose than a solid bar ; if, however, the 
bar be slit lengthwise down to the axis, the effect will be nearly equal to 
the wires, and if the copper case be sawed open lengthwise, it will not 
destroy the effect of the wires. 



104 Volta- Electric Induction. 

above it in the form of a flat spinal. Thus, let A (Fig. 54) 
(Davis's Manual, p. 149, Fig. 97) be a coil of copper ribbon, 
having the two ends connected with a battery. Let B be a 
second coil placed just above it, with its ends connected with 
the ends of a third coil C. Over this place a fourth coil W, 
with handles attached by wires to each extremity as above. 

Exp. 1. By passing the battery current through. A, secondary currents 
will be induced in B, one, when the circuit is completed, passing in a di- 
rection opposite to the battery current, called the initial, and one, when 
the battery current is broken, circulating in the same direction, and called 
the terminal current. 

Exp. 2. When C is connected with B, as in Fig. 54, the secondary cur- 
rent passes also through C, and will produce a tertiary current in W, and 
if W be a coil of fine wire, strong shocks are felt, by clasping the handles. 
A ribbon will give a quantity current, but its intensity will be slight com- 
pared with the fine wire coil. 

Tertiary currents are also induced both when the battery 
circuit is closed and when it is broken, and the initial and 
terminal tertiaries flow in directions opposite to the corres- 
ponding secondaries. Tertiary currents are capable of pro- 
ducing currents of a fourth order, and these latter current 
of a fifth order, and so on, as high at least as the seventh 
order. 

The directions of these currents, produced by the initial 
and terminal battery currents, are represented by the sign -f , 
when they flow in the same direction, and — , when in an 
opposite direction. 

At the beginning. At the ending. 

Thus, Primary current, -f- + 

Secondary current, — - + 

Tertiary current, + — 

Quaternary current, — + 

It will be seen that these induced currents must react upon 
each other, and diminish their effect, by inducing currents in 
an opposite direction. In this way also, induced currents 
act against the battery current, and this fact presents a 
serious difficulty in using this agent for moving machinery. 

There is a striking analogy between frictional and voltaic 



Masnetico-Ek ciion. 



105 



electricity, in the fact that both kinds induce electricity in 
bodies which are in their vicinity ; but there is also a markea 
difference in the circumstance that the presence of a body 
electrified by statical electricity, throws surrounding bodies 
into an excited state which is constant, while the currents in- 
duced by voltaic electricity are produced only at the moment 
that the battery currents commence and cease to flow. If 
the battery current is constant, no secondary currents will be 
induced after the first wave is excited. Hence the rapid suc- 
cession of shocks from the outer coil, when the battery cur- 
rent is rapidly broken and closed. 

IV. Magneto-Electric Induction. The power of the 
magnet to induce electricity greatly exceeds that of vol- 
taic currents. 

jf^ Fig. 55, 




The apparatus best fitted to exhibit this effect is the Mag- 
neto-Electric Machine, (Fig. 55,) which consists of a perma- 
nent horse-shoe magnet, SN, supported by pillars upon the 
stand Z, and an armature, g, wound with copper wire, and 
made to revolve upon an axis, c, near the poles of the magnet, 
by means of the wheel h; "one end of the wire is soldered to 
the axis, by which means it is connected with a break-piece, 
against which the- wire e presses; the other end of the wire 



Fine wires answer a better purpose than a solid bar ; if, however 
the bar be slit lengthwise down to the axis, the effect will be nearlv 
equal lo the wires, and if the copper case be sawed open lengthwise, 
it will not destroy the effect of the wires, 
5* 



10G Theory of Electro-Magnetism, etc. 

is soldered to a silver ferule, a, insulated from the axis, against 
which the wire b presses; the wires e b communicate with 
the cup into which the wire p is inserted ; the wire n is con- 
nected with the axis by means of the post on the right of b ; 
p and n therefore represent the two ends of the wire which 
surrounds the armature. When the armature is set in motion 
by the multiplying-wheel h, its magnetic state is continually 
changing. When the two extremities of the armature are 
midway between the poles of the magnet, the armature is 
neutral. As they advance towards the poles, they acquire a 
gradually-increasing polarity, until they are opposite the poles, 
and gradually diminish, as they pass the poles, until they are 
midway again between the poles, when the armature becomes 
neutral, as before. By this revolution, a current of elec- 
tricity will be induced in the wire which surrounds the arma- 
ture, and will pass from the break-piece to the ferule, by 
means of the wire e b, which connects them; excepting, 
when the end of the wire e is passing across the break-piece, 
then there will be induced in the wire which surrounds the 
armature a secondary current, which passes by sparks at each 
point of interruption, or at the wires p n, if they are brought 
nearly into contact. By pressing the hands, previously moist- 
ened, upon the handles connected with j? n, powerful shocks 
will be felt at each interruption. Deflagrations may also be 
produced, and decompositions effected, and generally the 
electricity thus induced produces effects precisely similar to 
those from the voltaic battery. The phenomena of elec- 
tricity, thus produced, are sometimes called Blagncto-Elec 
tricity* 

V. Theory of Electro-Magnetism and Magneto-Electricity . 
In order to understand the theory of M. Ampere, by which 
the phenomena of electro-magnetism and magneto-electricity 
may be best explained, it is only necessary to keep in view 
the following principle, which lies at the basis of the theory ■ 

When two positive or two negative currents are passing in 
the same direction, and parallel, they attract, and when pass- 
ing in opposite directions, they repel each other. 

* The best apparatus for experiments upon electro-magnetism and 
magneto-electricity, is manufactured by Daniel Davis, Jr. No. 11, 
Cornhill, Boston 



! 




Theory of Electro-Magnetism, etc. 107 

If, now, we suppose that all magnetic bodies, and the earth 
itself among the number, derive their magnetic properties 
from currents of electricity circulating, in reference to their 
axis, in one uniform direction of revolution, we can account 
for all the phenomena of Magnetism, Electro-Magnetism, and 
Magneto-Electricity. 

Fig. 56. 

To make this view clear. Suppose that //^f 
around the cylinder of Lteel, (Fig. 56,) at right |j^: 
angles to the axis, currents of positive electricity 
are constantly circulating in a direction opposite 
to that in which the sun moves. The cylinder 
n ill be a magnet, n the north pole, and S the 
south pole, and, if it be poised upon a pivot, it 
will differ in nothing but in form from a mag- 
netic needle. 



Application of the Theory. 1. The reason | 
tnat the needle turns to the east when the 
positive current passes above it from north to 
south is, that the currents in the magnet, and those in the 
wire, move in different directions. The needle is repelled, 
and turns so that the currents may coincide. 

2. When the positive current passes under the needle, it 
moves to the west, because then also the two positive currents 
coincide. 

3. When it passes on either side in the same horizontal 
plane, it tends to a vertical motion, for the same reason as 
above ; but if the positive current passes from south to north, 
the phenomena are all reversed. 

4. When it passes around the poles in a vertical plane, in 
the same direction in which the sun appears to move, the 
needle will perform one half a revolution, because the cur- 
rents move in opposite directions, and the needle revolves so 
that the currents in it may coincide with those in the con- 
da cting wire. 

5. Bars of steel and soft iron become magnetic when 
placed in the helix around which currents of electricity 
circulate, because similar currents are induced in them. 



108 Thermo-Electricity . 

6. If we suppose positive currents of electricity to be 
passing around the earth in the same direction in which the 
sun appears to move, they would convert it into a magnet, 
the north pole of the earth corresponding to the south pole of 
the magnetic needle ; hence, if soft iron or steel bars are placed 
in a north and south direction, they will become magnets by 
induction, the positive currents passing from west to east, 
because then they would coincide with the same currents in 
the earth which pass from east to west; hence the reason 
that a magnetic needle stands north and south, is, that the 
currents of electricity circulating around the earth, and those 
circulating in the needle, will coincide only when the needle 
takes that direction. 

VI. Thermo-Electricity. Thermo-electric phenomena re- 
sult from currents of electricity excited in metals by heat. 
The existence of these currents was first demonstrated in 
1821 by Seebeck. 

If a magnet be suspended in a rectangle formed of a bar 
of antimony or bismuth, having its extremities connected 
with copper wires, and heat applied to one end of the bar, 
the needle will be deflected in one direction, and in an 
opposite direction when heat is applied to the other end 
Similar effects are produced when either end is cooled below 
the natural temperature. Other metals, treated in the same 
manner, exhibit similar phenomena, but bismuth and an- 
timony are the best. Prof. Gumming has shown that a 
rotary motion may be produced by placing platinum and 
silver wires, soldered together in a circular form, upon a 
magnet, and applying heat. 

VII. Nature of Electricity Some suppose that there is 
no transfer of any thing in what are called electric currents, 
but a process of induction passing progressively along among 
the molecules of a conductor. Others ascribe them to waves 
of vibrating matter, just as the phenomena of light and 
caloric are explained, by the undulatory theory. 

VIII. Uses of Electricity. 1. Both voltaic and common 
electricity have been employed in medicine ; in some cases, 
with highly beneficial effects. It acts powerfully upon the 



Electro-Magnetic Telegraph. 



109 



nervous system, and has been the means of restoring sen- 
sation to parts of the body which had become paralytic ; 
so powerfully does it act upon the vital energies, that persons 
who have been deprived of life, either by some accident, or 
by design, have been resuscitated by its agency. Its influ 
ence is constant and universal in the animal, vegetable, and 
mineral kingdoms. 

2. Attempts have been made to employ voltaic electricity 
as a motive power in the arts, to supersede the use of 
steam ; but all attempts hitherto have been unsuccessful. Suf- 
ficient power has been generated to turn a small lathe ; and it 
is to be hoped that an apparatus will yet be constructed to 
render available the great force which this agent is capable 
of exerting. This force depends upon the property of the 
voltaic currents to communicate magnetism to soft iron, 
thus producing a powerful attraction, and the property of the 
iron to change its poles, and consequently its attracting and 
repelling power as currents circulate in different directions. 
(See Fig. 42.) 

3. Electro-Magnetic Telegraph. A most beautiful and 
highly useful application of voltaic electricity has lately 
l>een made, for the purpose of communicating intelligence 
from one place to another. The instrument is called the 
Electro-Magnetic Telegraph. The one invented by Prof. 
S. F. B. Morse appears to have been the most successful. 
It consists of an electro-magnet, m, (Fig. 57.) an armature 
connected with a lever balanced upon d, and having near the 

Fig. 57. 




110 Electro-Magnetic Telegraph. 

■end of its longer arm, a steel point or pen, which may be 
made to press against the roller. The paper passes around 
this roller, and is moved along by the clock-work c. When 
the circuit is closed, the electro-magnet is magnetized and 
attracts the armature upon its poles. This brings the pen in. 
contact with the paper pp, and produces a dot or line according 
to the time the current circulates. Thus, suppose the bat- 
tery at Washington and the telegraph in New York, with 
wires w w extending from the magnet to the battery. The op- 
erator in Washington, by closing the circuit, magnetizes the 
electro-magnet in New York, and brings the pen against the 
paper, and by breaking and closing the circuit, he can form 
*t series of characters consisting of dots and dashes, which 
are the symbols of letters or words ; thus information is com- 
municated with the rapidity of lightning. It is found that 
one wire is sufficient for the effect, if opposite poles at the two 
extremities are connected with a plate buried in the ground. 
It is found also, that several telegraphs, on the same wire, 
may be worked along the line, or at the two extremities of 
it. A bell b is usually attached, which is to notify the opera- 
tor at the station that intelligence is expected ; at the same 
time also the clock-work is set in motion. 

The following is Morse's Telegraphic alphabet, with the 
*etters which the characters represent. 



Alphabet 
A 


- - 


Numerals. 


B •- 


p .-._ 


2 


C -- - 


Q 


3 _- _ _ 


D 


R - -- 


4 


E - 

F 


S 

T 

u . 


6 


H 




I -- 


w 


9 


L 


X 

Y -- -- 
Z 





M 

N 


& 





Electro- Magnetic Telegraph. Ill 



E 1 e c t r o M a 



g n e t i c Tel 

g r a p h i 

v e n t e d b 

y P ro fess 

o r . . M o r sein 

18 3 2 

House's Lightning Printing Press. Mr. House has invent- 
ed a very ingenious Telegraph, which he has designated 
by the ,above name, in which type are used to print the com-, 
mon letters on strips of paper. It is a very beautiful in- 
vention. 

In the practical operation of the Electro-Telegraph, there 
are many influences which tend to obstruct it in its action — 

1. The wires are liable to be severed either by design or 
accident, and some time must elapse before they can be 
mended. 

2. The influence of thunder storms upon the wires, by in- 
duction will cause a flow of electricity, and put the machine 
into operation at a distant station. 

3. Lightning sometimes strikes the wires and either melts 
them off or travels to the different stations, affecting the ope- 
rators with very powerful shocks. 

4. A difference of temperature at the two extremities of a 
long wire, will often produce currents of electricity in the 
wires, which obstruct the regular communications. 

In these and some other ways, communications are liable 
to be interrupted ; but notwithstanding these obstacles, it has 
proved eminently successful. Most of the principal cities in 
ihe United States are already connected by telegraphic lines, 
and the time cannot be far distant when not only every por- 
tion of this country, but the extremes of every continent of 
the earth, will be closely united bv means of this truly won- 
derful and useful invention. 



112 



Electricity. — Elcctrography . 



4. Electrography. A still more recent application oi 
voltaic electricity has been made to the "production oi 
perfect metallic casts or copies of medals, copperplates, and 
other works of art." The discovery appears to have been 
made about the same time, by Prof. Jacobi, of St. Petersburg, 
and Mr. Spencer, of Liverpool. The instrument by which 
this effect is produced is the 

Electrotype ; and the effect depends upon the decomposition 
of some metallic salt, by which the metal is precipitated upon 
the object to be copied, either forming a mould for the cast, 
or raising lines which may be used for making impressions 

on paper or other materials.* 

Fig. 58. 

Fig. 58 represents one form of the 
electrotype, and the mode of taking 
impressions. A is a glass vessel, in 
which a division is made by casting 
across it plaster of Paris, (earthen 
ware, a bladder, or any porous mem- 
brane, as thick pasteboard, will answer 
the same purpose.) Into one of the 
partitions is put a saturated solution 
of sulphate of copper, and into the 
other acidulated water. The object 
C to be copied is soldered to one end of a wire, d } and a 
piece of zinc, Z, to the other end ; the object is then immersed 
in the cupreous solution, and the zinc into the acidulated 
water. The deposit of metallic copper then commences 
upon the object c, copying, with the most scrupulous exact- 
ness, every line, and even the shades of polish. In about 
two or three days, a complete mould may be obtained. 
The copper mould is separated from the matrix by gentle 
heat. 

Theory. The metallic salt and the water are both decomposed. The 
sulphate of copper is resolved into sulphuric acid and oxide of copper 
the water into oxygen and hydrogen. The acid and oxygen go to the 
zinc, and the hydrogen and the oxide of copper to the copper pole, ths 
hydrogen unites with the oxygen of the oxide of copper, and the me 
tallic copper is deposited upon the metal or object to be copied. 




* For a description of this process, see Davis's Manual of Magnetism, 
p. 199, Seq. 



fi 






PART II. 

CHEMICAL AFFINITY. 



In all those phenomena, which appropriately come undex 
the obseivation of the chemist, chemical affinity is the great 
cause to which they are referred. Other agents, as light, 
heat, electricity, cohesion, etc., modify its action, and some 
knowledge of them is therefore an essential preparation foi 
the study of this, — the great subject of chemistry. The de- 
tails, to which we shall attend in the examination of particu- 
lar substances, are, almost exclusively, but the effects of this 
principle. The student, therefore, should be familiar with 
the circumstances which modify its action, its varieties or 
different modes of operation, its effects, and especially the 
laws in accordance with which these effects are produced. 

Chemical Affinity is an attraction, which acts only at in- 
sensible distances, between particles of different kinds, and 
forms a new substance* Cohesion is distinguished from it, 
by acting only between particles of the same kind, as well as 
by being governed by different laws. 

Varieties of Chemical Affinity. 

Although this power is the same in all cases, it will facili- 
tate the progress of the student to distinguish some of the 



A late writer (Griffin, Chemical Recreations) maintains that there 
is no such thing as chemical affinity, because we know merely that 
bodies combine. We might as well deny that any force or power ex- 
ists because we see only its effects. From the fact that bodies do com- 
bine, we infer that some power causes them to combine, although 
indeed, we know nothing of it, except in its effects. 



114 Varieties of Chemical Affinity. 

different cases in which it operates. Between many sub- 
stances it does not exist at all, as is seen in mixing oil and 
water. The most simple case is the direct union of two sub- 
stances, as when oxygen gas and iron unite, and form iron 
rust. This is called Simple Affinity. The combination of 
alcohol with camphor is another example. 

Exp. But if water be added to this solution of camphor, the alcohoi 
will combine with the water, and desert the camphor, which again ap- 
pears free, or is technically said to be precipitated. As the alcohol 
appears to choose the water in preference to camphor, such cases are 
called examples of single elective affinity* 

The following are examples of the same kind : — 
Exp. Into a solution of sulphate of copper (blue vitriol) immerse a 
clean iron wire ; the sulphuric acid (oil of vitriol) will elect the iron, 
and the copper will be precipitated, forming a metallic coating upon 
the wire. 

Exp. Into a solution of protonitrate of mercury put a sheet of cop- 
per, or cents, well cleaned with dilute sulphuric acid ; the nitric acid 
will elect the copper, and the metallic mercury will be precipitated, 
and form a covering over the cents, which will give them the appear- 
ance of silver. 

But, in other cases, two compounds mutually decompose 

each other, and form two new compounds. 

Exp. Thus, if carbonate of ammonia and hydrochlorate of lime be 
mingled, each will be decomposed. The former consisting of carbonic 
acid and ammonia, and the latter of hydrochloric acid and lime, the 
carbonic acid will unite with the lime, and the hydrochloric acid with 
the ammonia, forming carbonate of lime, and hydrochlorate of ammo- 
nia. This change may be very easily understood from the annexed 
formula, in which the symbols are used.t 

C + Am 

C abandons Am. and goes to Ca; at the 

same time HC1 abandons Ca, and goes to Am. ; • 

and the results are C -f- Ca. and HC1 -4- Am. 

HC1 + Ca. 

*" Elective affinity is the basis of chemical science ; for if each sub- 
stance attracted every other with the same force, when combination 
had once been effected, the decomposition of many, if not of most 
substances, would be impossible ; hence there would be but few 
changes in matter which would come under the investigation of the 
chemist. 

f C= Carbonic acid, and Am. = Ammonia ; HC1 = Hydrochloric 
acid, and Ca. = Lime. 



Operation of Chemical Affinity. 115 

Exp. To a solution of alum (sulphate of alumina and potassa) add 
a solution of acetate of lead. Sulphate of lead and acetate of alumina 
are formed by a double decomposition. The sulphate of lead will be 
precipitated, and the acetate of alumina will remain in solution. 

Exp. Nitrate of ammonia and sulphate of soda will mutually decom- 
pose each other. In all cases of double decomposition, the alkali in one 
of the compounds will just neutralize the acid in the other, so that, if 
any delicate test of an acid or an alkali (as vegetable infusion) be 
placed in the mixture, no effect will be produced upon it} hence, as 
the quantities of acid and of alkali, in all neutral salts, are just suffi- 
cient to saturate each other when double decomposition takes place, 
these quantities are called equivalents. 

Such cases are examples of double elective affinity* Cases 

are more numerous, however, in which the changes are much 

more complicated ; but they may all be referred to the three 

modes stated above. 

Circumstances which modify the Operation of Chemical 
Affinity. 

That one substance has a stronger affinity for some than 
for others, cannot be doubted. But combination and decom- 
position do not always depend upon the relative force of af- 
finity alone. Several circumstances modify the operation 
of this power. These are, cohesion, elasticity, quantity of 
matter, gravity, and the imponderable agents. 

I. Cohesion. In order that substances should combine 
with each other, it is necessary that their particles should be- 
in contact. But cohesion holds together the particles of each 
substance, so that they cannot be freely intermingled. Co- 
hesion must, therefore, be destroyed to facilitate chemical 
action. This may be effected in three ways : — 

1. By reducing the substance to powder. 

Exp. Take two pieces of crystallized nitrate of copper ; roll one of 
them up in tin foil ; grind the other to powder, and wrap it in a piece 
of the same metal ; drop a little water upon both as they are rolled 
up. In a few minutes, that which is pulverized will combine with 
the metal, and burst into a flame, while the other will not be affected. 

Exp. Take two equal portions of chalk, and pulverize ■ one ; pour 

* Sina-Je and double elective affinity are the same in principle. Tbe 
only difference is, that, in the one case, a compound is decomposed by 
a third substance, and but two affinities are in operation, while, in the 
other, two compounds mutually decompose each other, and four affin- 
ities are brought into action. 



116 Operation of Chemical Affinity. 

dilute sulphuric acid on each, and the action will be rapid in the case 
of the pulverized chalk, but moderate in the other case. In this ex- 
periment, one of the substances is in solution; and usually it will be 
found insufficient to pulverize both substances, and resort must be haa 
to the second method. 

2. By dissolving the body in some liquid. 

Exp. Mix together tartaric acid and carbonate of soda; no action 
will follow; pour on water, and they will be dissolved, and a violent 
action ensue. 

Solution is effected when a solid is put into a liquid, and 
entirely disappears, leaving the liquor clear. The body 
which thus disappears is said to be soluble ; the liquid is 
called a solvent, and the compound liquor a solution. Water 
is the principal solvent; alcohol, ether, oils, alkalies, and 
acids, are also employed. When water, or any solvent, has 
dissolved as much of any substance as it can, it is said to be 
saturated, and the solution is called a saturated solution. 

Solution should not be confounded with diffusion, which 

is merely a mechanical mixture. 

Exp. This distinction may be seen by mixing magnesia in water. 
The particles of magnesia are suspended at first in the water, rendering 
it turbid, and they would soon subside to the bottom ; but if nitric acid be 
added, the magnesia will be dissolved, and the water will become clear. 

Most substances are more soluble in hot than in cold 
water; as a hot saturated solution cools, the water will not 
therefore be able to hold in solution all of the substance 
which had been dissolved, and it appears again in a solid 
state. The power of cohesion has the ascendency over the 
affinity of the liquid for the solid, and forms the latter into 
crystals. Hence the phenomena of crystallization are owing 
to the ascendency of cohesion over affinity. 

By evaporation, also, the solid may be recovered from so- 
lution. In either case, the crystallization is often confused, 
especially when the process is rapid. 

Insolubility has been found to exert a remarkable influence 
on affinity, in the case of an alkali with two acids, or an acid 
with two alkalies, one of which will form with the alkali a 
soluble, and the other an insoluble compound. The one 
which is insoluble is always formed in preference to the solu- 
ble compound. 

Exp. Thus, if nitric and sulphuric acids and baryta be thrown to- 
gether in water, sulphate of baryta, which is insoluble, will be formed 
in preference to nitrate of baryta, which is soluble. 

It is obvious that, while the solution of one of the substances 



Operation of Chemical Affinity. 117 

is usually necessary, the solution of both will further facilitate 
the action. 

3. By heat. — Fusion is the reduction of a solid to a liquid 
state by caloric, and facilitates chemical action by enabling 
the particles to intermingle, and come within the sphere of 
e:ich other's affinity. In liquids a slight degree of cohesion 
remains, and hence heat is applied to them with advantage. 
A hot liquid will act more powerfully upon most solids than 
the same liquid when cold. 

II. Elasticity. Cohesion, as we have seen, opposes 
chemical action by keeping the particles out of the sphere 
of each other's influence. Elasticity, or the gaseous state, 
is still more unfavorable to the operation of affinity, because 
the particles are removed too far from each other to be at- 
tracted ; hence most gases, though possessing a strong attrac- 
tion for each other, will not combine unless they are in the 
nascent state, that is, when in the act of assuming the gase- 
ous form. 

In this way elasticity not only prevents chemical union, 
but it favors decomposition. 

1. When two highly-elastic gases combine, forming a 
iiquid or solid, the compound will be decomposed by a very 
rlight cause: the chloride of nitrogen is a familiar example. 
It is an oily liquid, composed of two gases. A slight eleva- 

oi temperature will cause instant decomposition, even 

villi explosive violence. Generally all compounds which 

contain a volatile principle are easily decomposed by a high 

icrature. Hence caloric sometimes favors chemical action 

d stroying cohesion, while at others it prevents it, and 

favors decomposition by promoting elasticity. 

2. There are some gases, however, which readily combine 
at a high temperature, as in the case of gaseous explosive 

ires. Oxygen and hydrogen gases require the heat of 
flame to effect their union. The caloric, in such cases, ac- 
cording to Berthollet, expands the gases in immediate con- 
tact with the flame, which acts as a violent condensing force 
to contiguous portions, and brings them within the sphere of 
each other's attraction. The same explanation is applied to 
the combination of gases effected by passing electric shocks 
lluough them. 

III. Quantity of Matter. Oxygen combines with lead m 



118 Operation of Chemical Affinity, 

three proportions, forming three distinct compounds. The 
peroxide, or that which has the greatest quantity of oxygen, 
is easily decomposed by heat; the second compound, in 
which there is less oxygen, requires a higher temperature to 
effect decomposition; and the third, which has the least oxy 
gen, will sustain the heat of our furnaces without yielding up 
its oxygen. Hence, generally, when one substance combines 
with anothei in several proportions, the affinity is stronger in 
the case of the less than of the greater portions* 

On this principle, also, when a salt is dissolved in water, 
the first portions are dissolved more rapidly than the last, and 
the force of affinity diminishes up to the point of saturation, 
when it is overcome by the cohesion of the solid. 

This principle led Berthollet to account for all chemical 
changes without the aid of affinity, the existence of which he 
was disposed to e'eny; but M. Dulong has found that the 
principle of Bertho'let is not in accordance with the results 
of experiment. 

IV. Gravity. The influence of gravity on chemical action 
is seen when substances of different specific gravities com- 
bine; as, when two liquids are put together, the heavier 
liquid will sink to the bottom ; or, when salt is dissolved in 
water, the salt will remain at the bottom, and prevent the 
particles of water from coming into contact with those of 
the salt. 

V. Imponderable Agents. The influence of caloric over 
chemical phenomena has already been alluded to. It favors 
chemical action in the case of solids, by destroying cohesion, 
and opposes chemical action in the case of gases, by increas- 
ing their elasticity. The influence of light has already been 
noticed. Common electricity is often employed for the com- 
bination of gases, and galvanism for decompositions; but the 
same effects may be produced by either. 



* In consequence of the influence of quantity of matter over chern* 
teal changes, the chemist generally employs more of one substance 
than is necessary to effect the decomposition of another. 



Measure and Effects of Chemical Affinity. 119 



Measure of Affinity. 

Since some substances have a stronger affinity than others, 

attempts have been made to measure its different degrees of 

force. It was once supposed that its relative strength could 

be ascertained by the order of decomposition, as may be ex* 

plained from the following table: — 

Sulphuric Acid. 
Baryta, Lime, 

Strontia, Ammonia, 

Potassa, Magnesia. 

Soda, 

If to the sulphuric acid, united with the mSgnesia, forming 
the sulphate of magnesia, ammonia be added, the acid will 
leave the magnesia, and elect the ammonia, forming the sul- 
phate of ammonia. If to this, lime be added, the acid will 
desert the ammonia, and unite with the lime ; this again will 
be decomposed by the soda, and so on to baryta. Hence 
sulphuric acid has the strongest affinity for the baryta, and 
the force is in the order in which the several substances are 
arranged. 

Exp. This order may be shown experimentally thus : To a filtered solu 
tion of nitrate of silver add metallic mercury; the silver will be precip- 
itated, and the nitric acid will combine with mercury, forming the nitrate 
of mercury. Immerse in this a piece of clean sheet lead; the mercury 
will now be precipitated, and the lead will remain in solution. 

Suspend in this a strip of clean copper; the lead will be thrown down, 
and the nitrate of copper will remain in solution. 

In this place a sheet of bright iron, and in a short time the iron will 
displace the copper, forming a solution of nitrate of iron. 

To this present a piece of zinc ; the iron will be separated, and the 
zinc will combine with the acid. 

Add liquid ammonia ; the zinc will be separated, and nitrate of ammo 
nia remain in solution. 

To this pour lime water; the ammonia will be liberated in the form 
of a gas, and nitrate of lime remain in solution. 

Add to this oxalic acid, and the oxalate of lime will be thrown down, 
while a mixture of water and nitric acid remains. 

Hence the practical chemist, when he wishes to decom 
pose any compound, is enabled to decide upon the substance 
which will produce that effect. 

But the circumstances which modify the action of chemical 
affinity are so numerous, that the order of decomposition is 
not, in every case, the measure of affinity. To. determine the 



120 Effects of Chemical Affinity. 

relative force of affinity in doubtful cases, observe Jfche ten- 
dency of several substances to unite with the same, under 
the same circumstances ; and then notice the apparent facility 
of decomposition, when these compounds are exposed to the 
same decomposing agent. 

Effects of Affinity. 

The changes which accompany the action of affinity are 
changes of chemical properties — of color, form, temperature, 
and specific gravity. 

I. Change of Chemical Properties. It is one of the most 
remarkable facts, in chemistry, that, when two bodies combine 
chemically, the compound is generally possessed of properties 
entirely different from those of the components. 

Exp. 1. Pour sulphuric acid upon magnesia, and the compound will 
be Epsom salts, entirely unlike either. 

Exp. 2. Burn oxygen and hydrogen gases, and water will be 
formed, which is wholly different from either of its constituents. 

There are some cases in which affinity produces com- 
pounds without much change of properties, as in the case 
of solution ; but the force of affinity in such cases is very 
feeble. 

Exp. Salt dissolved in water, and camphor in alcohol, are instances. 

II. Change of color is often the effect of affinity. 

Exp. 1. To the chloride of calcium add nitrate of silver, both in 
solution ; a white precipitate will be formed, which is the chloride of 
silver. (See page 69.) 

Exp. 2. To a solution of nitrate of lead add a few drops of hydriodic 
acid, and a beautiful yellow pigment will be formed. 

Exp. 3. Into an infusion of purple cabbage pour a few drops of any 
alkali, and the color will become green ; add an acid gradually, drop 
by drop,* and the purple color will be restored; add a few drops more 

* For this and sim- 
ilar purposes,the drop- 
ping tube a (Fig. 59) 
may be used, ft is a 
glass tube, with a bulb, ." 
as a, with a small ap- 
erture at the smaller 
end, through which any liquid may be drawn up into the bulb by pla- 
cing the mouth upon the larger end. Having partially filled the bulb, 
place the thumb over this end, and, by admitting the air slowly, the 
liquid will drop out at the smaller eixL 




Effects of Chemical Affinity. 



121 




of acid, and it will become red. By the gradual addition of the alkali, 
the effects may now be reversed. 

III. Change of form frequently accompanies chemical 
combination. 

Exp. 1. Take oxygen and hydrogen gases, and explode them; they 
will form a liquid — water. Hence chemical affinity converts gases into 
liquids. 

Exp. 2. If the two gases, Fig. 60. 

ammonia and the hydrochlo- 
ric acid, be brought together 
in their nascent state, i. e., 
at the moment of their for- 
mation, they will produce 
the solid hydrochlorate of 
ammonia. Hence chemical 
affinity converts gases into 
solids. The two gases may 
be formed by putting hy- 
drochlorate of ammonia and 

lime in one retort, (Fig. 60,) and liquid hydrochloric acid in the other, 
and applying heat ; as the gases meet in the glass receiver b, they will 
combine and form a white solid. 

£27?. 3. Take chloride of calcium in solution, and pour in sulphuric 
acid ; a solid precipitate — the sulphate of lime — will be thrown down 
Hence affinity converts liquids into solids. 

Exp. 4. Into a solution of pearlash or saleratus pour sulphuric 
acid, and a portion of the liquid is converted into the form of a gas, 
which escapes with effervescence. 

Exp. Add one part of fuming nitric acid to two of alcohol ; both liquids 
will be converted into ammonia, and pass off in gas. Hence affinity 
converts liquids into gases. 

Exp. 5. Mix two solids, the nitrate of ammonia and sulphate of 
soda; on rubbing them in a mortar, they will become liquid. Hence 
chemical affinity converts solids into liquids. 

Exp. 6. Explode gunpowder; it will be wholly converted into gas 
Hence chemical affinity converts solids into gases. 

IV. Change of Temperature. The heat arising from the 

combustion of fuel, is owing to chemical action. 

Exp. Wet a piece of paper with spirits of turpentine and sulphuric 
acid, and then throw on a few grains of chlorate of potassa; the paper 
will instantly be in flames. 

V. Change of Specific Gravity. In changes of gases in*o 

liquids or solids, or of the latter into the former, there is, of 

course, a great change of density. But where there is no 

change of form, there is usually more or less of this change. 

Exp. Mix 100 measures of strong sulphuric acid with 100 of water, 
and the mixture will be less than 200 measures. 



122 Laws of Chemical Affinity. 

Laws of Chemical Affinity. 

The laws whicji regulate the action of affinity, constitute 
the most important part of the whole subject ; for they are the 
foundation of modern chemistry. As they are expressed 
mathematically, they have consequently imparted to it a high 
degree of accuracy, and greatly elevated its rank as a science, 
Most substances have been found to combine in definite pro- 
portions, and with such the laws of affinity are chiefly con- 
cerned ; but there are numerous cases of apparently indefinite 
proportions, which first demand a separate consideration. 

I. Indefinite Proportions. Of these there are two cases, 

in the first of which, any quantity of one substance may be 

combined with any quantity of another. Thus a drop of 

alcohol will combine with a quart of water, or a drop of water 

with a quart of alcohol. 

Exp. Take a large glass vessel, and fill it nearly full of water ; color 
it purple with the infusion of red cabbage; a drop of sulphuric acid will 
change it red, or a drop of alkali will give it a green color, which shows 
that both the acid and the alkali must combine with the whole of the 
water. 

In the second case, the proportions are indefinite within 
certain limits. Thus with 2J lbs. of water, a pound or any 
less quantity of common salt will combine, but if a larger 
quantity of salt be employed, all the excess above a pound 
will remain undissolved. The limit to the process is the 
point of saturation. (See page 108.) 

The most common instances of indefinite proportions are 
solutions where the proportions are indefinite below the point 
of saturation. Instances of unlimited indefinite proportions 
are less numerous. It is important to observe, in these cases, 
that the force of affinity is usually feeble, and the change of 
properties slight. Thus, in the common liquors, the properties 
of the alcohol are slightly modified by its combination with 
water ; and in solutions there is also little change. 

II. Definite Proportions by Weight. In the most numerous 
and interesting cases of chemical combination, a certain 
portion of one substance unites with one, two, three, ox 



Laws of Chemical Affinity. 123 

more tmes a given weight of another. These cases are 
usually characterized by a greater energy of combination, 
and a much greater change of properties than those which 
have been described. The great lav/ of definite proportions 
by weight may be thus stated : — 

1. The proportions in which substances combine may be 
expressed by fixed numbers, or by the multiples of these num- 
bers. The following table is an illustration : — 

Water is composed of Hydrogen 1 part -}- Oxygen 8 parts. 



Binoxide of Hydrogen 


1 


a 


+ 


" 16 


Protoxide of Nitrogen 


J Nitrogen 14 


it 


-h 


» 8 


Binoxide 


" " 14 


it 


+ 


" 16 


Hyponitrous acid 


» " 14 


it 


+ 


« 24 


Nitrous acid 


' " 14 


a 


4- 


» 32 


Nitric acid 


t u 14 


t i 




" 40 



A comparison of all the cases shows that hydrogen enters 
into combination in less quantity relatively than any other 
substance. It is therefore taken for a standard of comparison, 
and in the above table appears as unity. The lowest ratio 
in which oxygen combines with other substances is eight 
times that of hydrogen. The lowest combining ratio of nitro- 
gen is fourteen. If any simple substance does not combine 
with hydrogen, its lowest combining ratio may be ascertained 
from its combination with any other substance, whose ratio 
has been determined. Thus from the above table the com- 
bining ratio of nitrogen is seen in its compounds with oxy- 
gen, whose ratio was ascertained in its compounds with 
hydrogen. The lowest combining ratio is also called an 
equivalent, ox proportional. (See page 107.) 

Inspection of the above table will show, that while eight is 
the lowest combining ratio of oxygen, it combines also in the 
ratio of 16, 24, 32, and 40 parts; that is, two, three, four, 
and five times the lowest ratio, agreeable to the above-men- 
tioned law. 

There are some cases in which substances do not unite 
with one equivalent of one to one, two, or more equivalents 
of another, but apparently of one to one and a half. Such 
an irregularity conforms to the general law, on the supposi- 



124 Laos tf Chemical Affinity. 

tion that two of the former unite with three of the latter. In 
some cases, also, two equivalents of one substance unite with 
five of another. 

The law of definite proportions by weight may be thus 
illustrated algebraically : — If z and y be the equivalents of 
any two substances, their compounds must be x-\-y, z-\- c Z y t 
x-\-Zy, x-\-A y, etc. ; sometimes we shall have 2 x-\-S y, 
and rarely 2 x-\-5 y. 

It is evident from the above that the equivalent of any 
compound is_ the sum of the equivalents of its constituents, 
each being multiplied by the number of times it enters into 
the combination. Thus, in the above table, the equivalent of 
water is 1 -|- 8 = 9, of nitric acid, 14 — j— 40 = 54, etc. 

2. The second law of definite proportions is the follow- 
ing:— 

Every substance has its constitution invariable. Thus 
nitric acid is always composed of one equivalent of nitrogen 
and five of oxygen. No other substances, and no other 
number of equivalents of these, by combination can form 
nitric acid. 

The same is true of every substance whose elements com- 
bine in definite proportions. The least change of these de- 
terminate quantities will either form an entirely different sub- 
stance, or a portion of that substance which is :n excess will 
remain uncombined ; hence whatever be the circumstances 
under which chemical substances are formed, whether formed 
ages ago by the hand of nature, or quite recently by the 
agency of the chemist, their composition is always inva 

able. 

The merit of establishing this law is due to Wenzel, a 
Saxon chemist, who published his views in 1777. But Dr 
Dalton, an eminent English chemist, discovered the first law, 
and deduced from the scattered facts a theory of chemical 
union, embracing the whole science, and first published m 
1803. Drs. Wollaston, Thompson, and other chemists, foU 
.'owed out these views. But to no one, in this department, ?s 
science so much indebted as to Berzelius 



Laws of Chemical Affinity. 125 

The application of these laws, in the arts, is of immense 
importance. In the manufacture of compounds, they teach 
precisely what proportions of the ingredients should be used 
If these are expensive, an excess of one would be a seri- 
ous loss. 

III. Definite Proportions by Volume. The principal law 
of definite proportions by volume is precisely similar to that 
of definite proportions by weight, the parts being determined 
by measure, as in the former cd!se by weight. This law holds 
true only in the case of gases and vapors. It is supposed 
that substances which have not yet been made to assume 
the form of a gas or vapor, would conform to this law, if 
they should assume such form. The law may be illustrated 
by the following table: — 

100 vols, carbonic acid gas combine with 100 of ammoniacal gas. 

U a u « goo « 

" fluoboric " " 100 " 

" « " " 200 « 

But there are two laws of definite proportions by volume, 
which do not hold true to the same extent in definite propor- 
tions by weight. The first is, that a simple ratio of one to 
two, one to three, &.c, exists between the volumes of differ- 
ent constituents in the same compound. This may be seen 
in the above table. 

The second law is, that, in combination, gases and vapors 
are condensed by a portion, which is in a simple ratio to the 
itolume of one of the constituents. 

The laws of definite proportion by weight and by volume 
are not inconsistent with each other, for the specific gravity 
always bears such a relation to the combining ratio by volume 
as to establish their harmony. Thus hydrogen and oxygen 
combine in the ratio of two of the former to one of the latter 
by volume, and of one to eight by weight. But as oxygen is 
sixteen times heavier than hydrogen, one volume of it is eight 
times as heavy as two of the latter. In other words, the 
compound ratio of the specific gravity and of the equiva 
lents by volume, is equal to the ratio of the equivalents by 
weight. 




*26 The Atomic Theory. 

Atomic Theory. 

Existence of Atoms. The atomic theory supposes mattei 
to be composed of minute, indivisible atoms. Hypotheti- 
cal!}', matter is infinitely divisible, that is, to Almighty power 
out in fact it is not infinitely divided. Sir Isaac Newton re- 
garded it as probable, "that the primitive particles, being 
solids, are incomparably harder than any porous bodies com- 
pounded of them, even so very hard as never to wear, or 
break in pieces ; no ordinary power being able to divide what 
God himself made one in the first creation." 

Theory of definite Proportions by Weight. When sub- 
stances combine in their lowest equivalents, they unite atom 
to atom, (Fig. 61 ;) pig# 61# 

in higher proportions, 

one atom of one to g^^^jgggj^miisgSL 
two, three, or more 
atoms of the other. 
This theory exactly accounts for the facts of definite propor- 
tions ; for if in one compound we have one atom of A 
joined to one of B, and in another one of A joined to 
two of J8, through the whole mass, the sum total of S in the 
latter case will be exactly twice as much as in the former 
case. 

Atomic Weight. If in a compound of one grain of hydro- 
gen with eight of oxygen there be an equal number of atoms 
of each, an atom of the latter will be eight times as heavy as 
an atom of the former. In this way we know the relative 
M r eights of the atoms of all substances, whose equivalents are 
known) As the numbers are the same, the terms are often 
interchanged. 

The absolute weight and magnitude of atoms cannot be 
determined. Dr. Thompson calculates that a cubic inch of 
lead contains more than 883,492,000,000 atoms. 

The shape of atoms is matter of hypothesis. They are 
generally supposed to be spheroidal. 



Isomerism. — Cause of Cliemical Affinity. 127 



isomerism. 



It was formerly supposed that when two elements combine 
tn the same ratio, they must always give rise to the same 
compound ; but it has of late been discovered that this is not 
always the case. Thus there are 3 compounds of oxygen 
and phosphorus, whose composition is identical, each being 
composed of 31.4 parts by weight of phosphorus, and 40 
parts by weight of oxygen ; and yet these substances differ in 
their properties. The same is true of the two cyanic acids. 
Berzelius has applied to such compounds, as a class, the 
general term isomeric, from two Greek words,* which ex- 
presses an equality in the ingredients ; and to distinguish the 
isomeric bodies from each other the terms parai and meta 
are prefixed. 

To reconcile the phenomena of isomerism with the theories 
of chemical combination, we have only to suppose that the 
same elements may combine in different ways, so as to give 
rise to compounds essentially distinct ; for example, we may 
suppose that the 2 atoms of phosphorus and the 5 atoms of 
oxygen, which form 3 isomeric bodies, may be grouped dif- 
ferently; thus, 2 atoms of oxygen may first unite with the 

2 of phosphorus, and this compound unite with the other 

3 atoms of oxygen, or 4 of oxygen may unite with 1 of 
phosphorus, and 1 of oxygen with 1 of phosphorus : these two 
compounds may then combine, and form a different sub- 
stance from the first, although both contain the same number 
of atoms of each element. It is evident that these groups 
may be varied still further ; hence the kind of substance may 
depend upon the order in which the atoms are united. In a 
few cases, the equivalents of isomeric bodies differ : olefiant 
gas and etherine are an example. The equivalent of olefiant 
gas is 14.24, and that of etherine 28.48, or exactly double. 

Cause of Chemical Affinity. 

The cause of affinity has been supposed to be electricity. It 
appears that when two substances combine, they are in oppo- 
site states of electricity. It is believed to accord best with the 

* Jaog, equil, and /uegos, part. t IIuou, near to. 



128 Cause of Chemical Affinity. 

simplicity every where observed in the laws of nature ta 
ascribe the phenomena of electricity, galvanism, magnetism, 
and chemical affinity, to one and the same agent. By such a 
generalization we seem to be progressing in the chain of 
causation nearer to the great and ultimate cause, the agency 
of God. But such a view, in the present state of science 
cannot be maintained; and, although these agents have many 
points of resemblance, they differ in too many respects to be 
regarded as identical. In fact, we should be under the 
necessity of believing that a force might modify, increase, 
diminish, counteract, and overcome, itself. Some suppose 
that what we call the agents and laws of nature, have no 
real existence as distinct powers. They deny the agency 
of second causes, and ascribe every operation of nature to 
the immediate power of God. Others suppose that there are 
real agents or causes dependent upon God, but possessed of 
power in themselves, to act as second causes, or subordinate 
agents, in the various phenomena of matter. Whichever 
view we take, we must, in the end, refer the ultimate cause 
to the impulse of the divine will ; although, for the mere 
purposes of scientific classification, something, perhaps, ig 
gained by the introduction of second causes. 



PART III. 



PONDERABLE BODIES 



Specific Gravity means the relative weight of different 
substances, compared with some standard. In the case of 
solids and liquids, the weight of the body is compared with 
water as unity ; i. e., if a given quantity of water by measure 
be weighed,* and that weight represented by 1, the weight 
of an equal quantity by measure of any other substance is 
compared with it. In the case of gases, air is taken for the 
standard of comparison, or for unity, and an equal quantity 
of any other gas is weighed, and compared with it. 

There are several methods of ascertaining the specific 
gravities of bodies. 

1. One of the best, if the body is a 
solid, is to weigh it in the air, and then 
in water, in a manner represented in 
Fig. 62. If the body weighs 100 grains 
in the air, and 60 grains in water, then, 
to ascertain its specific gravity, institute 
the following proportion: As 100 — 60, 
or 40 : 100 : : 1 : 2.5; hence the sp. gr. 
of the body is 2.5, or two and a half 
times as heavy as water. If the solid is 
lighter than water, suspend to it a body 
heavier than water, whose specific gravity 
is known, and then weigh it as in the first instance. 

2. To ascertain the specific gravity of liquids, the Areom* 
tier is a convenient instrument. It consists of a tube, 




A cubic foot of distilled water weighs 62.5 lbs. 
6* 



ISO Nomenclature. 

a, (Fig. 63,) graduated with numbers, upon the end Fig. G3. 
of which are two balls, the lower filled with mer- Ij 

cury. If the instrument sink in distilled water to j 

1, it will sink below that mark in liquids which ^ — ifc^j 
are lighter than water, and will remain above it Hp-fcj-~ 4 
n those which are heavier. The specific gravity 
of each liquid is thus ascertained by the numbers 
on the scale. 

The specific gravity of liquids is also ascertained 
by the use of a small bottle containing just 1000 
grains of water ; by filling it with any other liquid, its weight 
will express directly its specific gravity. 

8. The specific gravity of gases is more difficult : a given 
portion of air is carefully weighed in a thin glass flask ; the 
air is then exhausted, and the flask weighed; the difference 
gives the weight of the air; this is taken for unity, and the 
weight of an equal quantity of any other gas is compared 
with it ; thus, 100 cubic inches of dry air, at 60° F. and 
80 in. barometer, weigh 31.0117 grains; 100 cubic inches of 
oxygen weigh 34.109 grains. Now, to ascertain the sp. gr 
of oxygen, institute the following proportion : — 

As 31.0117 : 84.109 : : 1, the sp. gr. of air, to 1.1025, 
the sp. gr. of oxygen. The sp. gr. of any other gas may bo 
found in the same way. 

Nomenclature. 

The study of particular substances has been greatly facili 
tated by the introduction of the nomenclature. By the use ol 
systematic names, expressive of the constitution of substances, 
the recollection of the name will call to mind the constitu 
tion ; while, on the other hand, if there be any difficulty in 
remembering names, the constitution will at once show what 
the name must be. Hence, although compounds are very 
numerous, the student can have no difficulty in remembering 
their names and constitution, for the one necessarily suggests 
the other. 

The present nomenclature was introduced in 1787 by the 
French chemists. It resulted from the labors of Lavoisier, 
Berthollet, Guyton-Morveau, and Fourcroy. Since that time, 
it has undergone but a few slight changes. The former no- 



Nomenclature. 



131 



menclature, if such the entire want of system could be 
called, was barbarous in the extreme ; fanciful names were 
introduced, and often many such were attached to the same 
substance. 

J . Simple Substances. The names of such elementary sub- 
stances as had long been known, remain unaltered, as of 
gold, ircn, etc. Those which have been discovered within 
the period of modern chemistry, have received names ex- 
pressive of some obvious property; thus the name oxygen 
signifies a generator of acids; iodine, violet-colored, from 
the beautiful color of its vapor ; chlorine, green, from the 
color of the gas. The following are the names of the simple 
substances, with their symbols annexed : — 



Oxygen, O. 

Chlorine, CI. 

Iodine, I. 

Bromine, Br. 

Fluorine, F. 

Hydrogen, H. 

Nitrogen, N. 

Carbon, C. 

Sulphur, S. 

Phosphorus, P. 

Boron, B. 

Silicon, Si. 

Selenium, Se. 






Potassium, (Kalium,) K. 

Sodium, (Natrium ) , Na. 

Lithium, L. 

Barium, . . .Ba. 

Strontium, Sr. 

Calcium, . . Ca. 

Magnesium, Mg. 

Aluminium, Al. 

Glucinum, G. 

Yttrium, Y. 

Thorium. Th. 

Zirconium, Zr. 

Manganese, Mn. 

Iron, (Ferrum,) Fe. 

Z .ac, Zn. 



Cadmium, Cd. 

Tin, (Stannum,) Sn. 

Cobalt, . , Co. 

Nickel,,. v<A Ni. 

Arsenic, As. 

Chromium, Cr. 

Vanadium, V. 

Molybdenum, Mo. 

Tungsten, (Wolfram,) W. 

Columbium, (Tantalum,) Ta. 

Antimony, (Stibium,) Sb 

Uranium, U. 

Cerium , Ce. 

Bismuth, Bi . 

Titanium, TL 

Tellurium, Te. 

Copper, (Cuprum.) .^. Cu. 

Lead, (Plumbum,) Pb. 

Mercury, (Hydrargyrum,) . . . .Hg 

Silver, (Argentum,) Ag. 

Gold, (Aurum,) Au. 

Platinum, PI , 

Palladium, Pd. 

Rhodium, R. 

Osmium, On 

Iridium, Ir 

Latanium La 



2. Acid Compounds. The names of acid compounds have a 
peculiar construction. All the acids formed by combination 
of oxygen with other substances, including a great majority 
of the whole number, take the name of the other substance, 
(winch is called the base,) changing its termination. If there 



i 32 Moment laiure, , 

be two oxygen acids formed with the same substance, the 
stronger, which contains more oxygen, takes the termination 
?c, and the weaker, ous. In the case of more numerous 
ecid compounds, the prefix hypo signifies inferiority, as in 
the following of oxygen with sulphur, beginning with the 
stronger, and proceeding to the weaker : — 

Sulphuric acid, Sulphurous acid, 

Hyposulphuric acid, Hyposulphurous acid. 

Sometimes the prefix per is used to indicate an additional, 
but indefinite quantity of oxygen. Thus perchloric acid 
contains more oxygen than chloric acid. 

Acids which do not contain oxygen receive names which 
are compounded of the names of their constituents, the first 
enunciated terminating in o, and the last in ic ; as, chloro- 
carbonic acid. Often the first is shortened ; as, fluo-boric, in 
stead of fluro-boric : this is the case with the hydrogen acids - 
as, hydrochloric acid, hydrosulphuric acid. 
8. Binary Compounds which are not Acids. In such com 
pounds, the names are composed of the names of their con 
stituents. In the compounds of oxygen, chlorine, iodine, 
bromine, and fluorine, with other substances, they are first 
enunciated, and receive the termination ide ; as, oxide of iron, 
chloride of iron, iodide of mercury, bromide of carbon, 
fluoride of zinc. In their compounds with each other, the 
order of enunciation is not essential, although it is com- 
monly that in which they are above mentioned; thus we 
may say, chloride of bromine, or bromide of chlorine ; but the 
former is more common. 

Compounds of the other non-metallic substances with each 
other and with the metals, receive names of similar construc- 
tion, except that the termination uret takes the place of ide; 
as, carburet of iron, bicarburet of hydrogen, sulphuret of 
arsenic. 

In many cases, one substance unites with another in 

several proportions, and the compounds are designated by 

numeral prefixes — proto the first, bi (formerly deuto was used) 

the second, ter the third, quadro the fourth, etc., and^er the 

* The & is omitted by some chemists, who write oxid for oxide, 



Nomenclature. \So 

highest degree, but indefinite ; sesqui signifies one and a half. 
If, however, the last enunciated substance, or base, be in two 
or more proportions, the dividing prefixes di, tri, etc., are 
used; subsequi indicates one and a half of the base. 

The following table exhibits all the cases of the use of 
numeral prefixes : 

Triphosphuret of copper =1 equiv. phosphorus and 3 equiv. copper 

Dinoxide of copper =-1 " oxygen and 2 " copper. 

Subse9!|Uiphospliuret of copper =1 M phosphorus and }£ " copper. 

Protoxide of copper =1 " oxygen and 1 " copper. 

Sesquioxide of manganese =1^ " oxygen audi " manganese. 

Binoxide of manganese = 2 " oxygen audi " manganese. 

Teriodide of nitrogen =3 " iodine and 1 " nitrogen. 

Quadrochloride of nitrogen =4 " chlorine and! " nitrogen. 
Peroxide of iron = iron oxidated in the highest degree. 

Many metals, whose names terminate in um, merely change 
turn or um into a to indicate the state of protoxide. Thus 
potassa = protoxide of potassium, lithia == protoxide of lithi- 
um, etc. The protoxide of calcium has long been known by 
the name of lime. 

Alloys, or compounds of metals with each other, not being 
yet reduced to the laws of definite proportions, have no sys- 
tematic names. 

Some binary compounds, whose combinations are analo- 
gous to those of simple substances, receive simple names, 
which in composition receive the termination uret, and follow 
the rules above given. These are ammonia and cyanogen. 
Another binary compound, water, forms compounds which 
are called hydrates ; as, hydrate of lime. 

4 Ternary Compounds, or Salts. These are formed by the 
combination of acids with other binary compounds, which 
are called, in reference to them, bases. The name of a salt 
is composed of the names of the acid and base. If the name 
of the acid have a termination ic, it is changed into ate ; ous 
is changed into ite. Numeral prefixes are used according 
to the rules which have been given, as in the following ex- 
amples : — 

Oinitrate of the protoxide of lead = 1 eq. nitric acid and 2 eq,. protoxide of lead 
u rotonitrate of mercury • = 1 " " and 1 " " of mercury 

Sesquteulphate of potassa = 1£ " sulphuric acid & 1 " potassa. 

Bisulphateof peroxide of mercury = 2 " ' and 1 " perox. of mercury 

Tersulphate of alumina =3 " and ] " alumina. 



134 Notation. 

As the acids never unite with the metals directly, but gen 
erally with their oxides, and sometimes other compounds, in 
the case of the oxides, the name is abbreviated: thus, by 
protonitrate of mercury is always understood protonitrate of 
the protoxide of mercury. Also, the prefix proto is often 
understood, and we say, nitrate of mercury. 

There are many ternary compounds, little known, how- 
ever, except to the chemist, called sulphur salts, and haloid 
salts, whose nomenclature follows the rules of binary com- 
pounds which are not acid. 

Notation, 

Notwithstanding the great advantages of the chemical no- 
menclature, a much greater help is given to the student in 
the notation. By this, as in algebra, long and intricate pro- 
cesses are exhibited to the eye at a glance, and the relations 
of the constituents in complicated compounds easily compre- 
hended. Each element is represented by a symbol consisting 
of its initial, or, in the case of two or more which have the 
same initial, of the initial and one of the following letters, 
as on page 123, where the symbols of all the elementary 
substances are given. In the case of potassium, sodium, 
tin, iron, and several others, the symbols are derived, from 
the Latin names. 

The symbols of compounds are composed of the symbols 
of their constituents, algebraically connected; as, Fe-|-Cl, 
chloride of iron. In binary compounds, the sign -j^ is often 
omitted. Coefficients are used to show the number of equiv- 
alents ; as, N-}-4Cl, quadrochloride of nitrogen ; or, if several 
symbols are written together without the sign -f-> an index is 
substituted for the coefficient, because the coefficient multi- 
plies all which come between it and the next sign. Thus 
the symbol of the substance last mentioned may be written 
NCI 4 . Some Chemists place the index thus N"C1 4 . 

Cyanogen, ammonia, and water, although compounds, have 
simple symbols, like the elements ; thus we have Cy, Am, and 
Aq, (Aqua,) instead of NC 2 , H 3 N, and HO 



Notation 135 

The symbols of oxygen and sulphur are abbreviated. The 
symbols for the compounds of oxygen are written thus: — 
N for N+oO, N for N + 40, N for N + 30, etc., each dot 
indicating an equivalent of oxygen. A comma is used in the 
same manner for the compounds of sulphur; thus, P for PS 
In place of the coefficient 2, a dash is often drawn through or 
beneath the symbol. This is very convenient in the case of 
half equivalents ; as, Mn, signifying 2Mn-|-30, that is, Mn-f 
liO, aesquioxide of manganese. In compounds of compli- 
cated constitution, it is often necessary to multiply several 
terms by one number, or to connect them as a whole to 
another term. This is done, as in algebra, by the use of 

vincula or parentheses; thus (K-f-2S)-[- Aq, shows that Aq 
is combined with K-|-2S, as with one substance; but if the 
parentheses were omitted, thus, K-|-2S-f-Aq, the symbol 
would indicate a combination of three distinct substances, 
each one with the other. Also in 2(K-f-2S), the first coeffi- 
cient belongs to what is within the parentheses as to one 
substance. 

If the student will, for practice, explain the constitution and 
give the names of the compounds in the annexed table, he will 
become familiar with the rules of nomenclature and notation. 

The following table contains the names, equivalents, and 
symbols of the thirteen non-metallic elements, and the sym- 
bols of their compounds with each other, in the order in 
which they are described in this work : — 

Oxygen, equiv. 8; symbol, O. -^ 

Chlorine, " 35.42 « CI, Cl + O, Cl + 40, CI + 50, CI +70. 

Iodine, « 126.3 « I, I + 50, I + 70, 3C1 + I. 

Bromine, ; 78 " Br, Br + 50 or BrO 5 . 

Fluorine, - 18.68 " F. 

(Ivdrocen « 1 (( (H, H + or H, H + 20 or H, H + Cl, 

Hydrogen, 1 £ H + I, H + Br, H + F or HF. 

( 1iie „ Cn.NO or N, NO 2 or N, NO 3 or N, NO* 
Vitrogen, " 14.15 " < . . 

( or N, NO 5 or N, NCI*, Nl 3 , NH 3 . 



136 Chemical Substances. — Oxygen. 

f C, C, C, C-f CI, C 4 CP, C ? C1, COP, C-l 
Ca rb „„, e qui v.6, 2;Sym .i %m™^™dM\t% 

^CyCl 2 , HCyS 9 , CyS 2 , H 2 CyS 2 . 
Sulphur, "16.1 . p, SO 2 , S03, SO^ ; SO^, S 2 C1, SCI, H9 
( HS 2 , CS 2 . 

Phosphorus " 15 7 « 5 P < p2 °' p3 °> p2 ° 3 > p2 ° 5 > p2C13 > psc,5 » Pi 
± nospnorus, id.7 £ p2Pj pjB ^ p2Br5? R3p2 

Boron, " 10.9 " B, B-f 30, B + 3C1, B-f 3F. 

'■.'''. nn ' r Se, Se-f-O or Se, Se-}-20 or Se, Se-f 3Q 

Selenium, « 39.6 " \ ... ? > "r 

i or Se. 
Silicon, " 22.5 " Si, Si + O, SiCl, SiBr, SiS, SiF. 



CHAPTER I. 

CHEMICAL SUBSTANCES. 

These substances will be arranged in three classes : 1st, 
non-metallic elements, and their primary compounds, with 
each other ; 2d, metals, with their primary compounds ; and 
3d, secondary compounds, or salts. 

Class I, Non-metallic Elements and their Primary Com* 
pounds with each other. 

Sect. 1. Oxygen. 

Symb .o. Eq uiv.^^.| s P . g ,{i 6 ™ £*=]: 

History. Oxygen was discovered by Dr. Priestley, of Eng- 
land, August, 1774, by exposing the red oxide of mercury to 
the solar focus. It. was also discovered by Scheele, a Swe- 
dish chemist, in 1775, and the same year by Lavoisier, of Paris, 
neither being acquainted with the discovery by the others. 
The honor of the discovery, as is usual in such cases, is as- 
cribed to Priestley , who called it depMogisticaied air; Scheele 
gave it the name o * empyreal air ; Condorcet, vital air ; and 
Lavoisier, oxygen. This latter name was suggested from the 
belief that it was the only acidifying principle in nature, It 



Pneumatic Cistern. 



137 



; is derived from two Greek words * sio-nifyino; a generator of 
I acids. It has since been found, however, that, although 
! present in most acids, it is not the only substance capable 
| of forming acid compounds. But, as a great majority of acids 
are oxygen acids, the name is not inappropriate. 

Natural History. Oxygen is the most abundant substance 

j known. It forms | of the atmosphere, § part of water. By 

far the greater part of the solid crust of the earth is composed 

of oxvdized substances, and it will not be far from the truth, 

I if we estimate oxygen to constitute § of all the matter with 

j which we are acquainted.! ' 

Processes. Oxygen can easily be obtained from the oxides 

i of metals, and from some of, the salts. The oxides of man- 

! ganese and of lead, and the chlorate of potassa, are most 

commonly used. The separation is effected by exposing 

; these substances to a red heat, in an iron retort, connected 

by a pipe with the pneumatic cistern. 

For the collection of gases which are not absorbed by 
1 water, the 

Pneumatic Cistern is 

I generally employed. Li 
consists of an oblong 

j box, C, (Fig. 64,) made 
water-tight ; b b, two 
shelves to support re- 
ceivers, as r ; w, a well 
filled with water, across 
which a board is placed, 
also to support receiv- 
ers, with small holes to 
let the gas through as it 

comes from the retort, which is placed over the side of the 
" ox* The shelves b 6 may be made for gasometers, or gas- 
wlders ; and in that case they are boxes open at the bottom 
of the cistern, with stop-cocks passing through one corner in 
the top of each. These are made air-tight by a lining of 
sheet lead. When they are filled with water, the gas is in- 
troduced, by means of a lead pipe, through an aperture in the 




* 'Ozvg and ytvvam. 

t If we suppose the sun and planets, with the stellary systems, to be 
! composed of matter similar to our earth, the quantity of oxygen which 
i actually exists must be immeasurably great. 



138 Oxygen. 

side of each, near the bottom; as it rises up, it displaces the 
water; I is a lamp-stand and retort,* as it is connected with 
the cistern.! 

Theory. To understand the theory of the process by man- 
ganese, it is necessary to notice the composition of its three 
oxides. 

Manganese. Oxygen. 

Protoxide, 27.7 or 1 equiv. + 8 or 1 equiv. = 35.7 

Sesquioxide, 27.7 « -f- 12 or 1£ " = 39.7 

Peroxide, 27.7 " -j- 16 or 2 « = 43.7 

The oxygen may be separated from the binoxide in two 
ways : — 

1. By simply exposing it to a "red heat. In this case, the 
binoxide parts with J equiv. of oxygen, and is converted into 
sesquioxide. 1 oz. of manganese will yield 128 cubic inches 
of oxygen. 

2. By putting it, in fine powder, into a glass flask, with an 
equal weight of concentrated sulphuric acid, and heating the 
mixture by a spirit lamp, the manganese parts with one equiv. 
of oxygen, and the sulphate of the protoxide of manganese 
remains. About twice the quantity of gas is obtained by 
this process, 1 oz. yielding 256 cubic inches of gas. But the 
former method is most convenient in practice. 

For these processes, the manganese should be previously 
ascertained to be free from carbonate of lime, which yields 
carbonic acid gas on being heated. J Oxygen obtained in 
this way is not quite pure, but is sufficiently good for all pur- 
poses of experiment. 

The gas obtained from chlorate of potassa is much purer, 
but more expensive. 

It may be easily obtained by subjecting the salt to a dulL 
red heat in a green or white glass flask, made without lead., 

* Retorts are either plain, as in Fig. Fig. 65. 

58, or tubulated, as Fig. 65. A Florence 
fiask will answer a good purpose, if a lead 
tube is fitted to it. See Fig. 66. 

t The cistern may be made of wood, 
or, what is better, of copper, of any con- 
venient dimensions. One five feet long, 
twenty inches wide, and twenty inches 
in height, is sufficiently large for com-, 
mon purposes. 

i It may be freed from carbonate of lime by washing it in dilute 
hydrochloric acid. 




Physical and Chemical Properties. 



139 



or in an iron retort.* It first becomes liquid, and is then 
resolved into oxygen and chloride of potassium. 

Theory. The chlorate of potassa is composed of chloric acid and 
potassa, and the theory of the process may be thus explained : KO -f- 
CLO 3 are resolved into K-f-CL, which remains in the flask, and 6 
equiv. of oxygen, which are collected over the cistern. One ounce oi 
chlorate of potassa will give about 640 cubic inches of oxygen. 

Physical Properties. Oxygen is transparent, colorless, 
tasteless, and inodorous. In the simple state, it always exists 
in the form of a gas. It cannot be condensed to a liquid 
r a solid, by pressure or cold. It refracts light the least 
| of all substances; is a non-conductor of electricity; is the 
only substance whose electric state is absolutely negative ; 
and of course it always goes to the positive pole in the 
galvanic circuit. Its specific gravity is 1.1026; conse- 
quently, 100 cubic inches, when the thermometer is at 60° 
Fahr. and the barometer at 30 inches, will weigh 34.1872 
grains. It is a little heavier than atmospheric air. 

Chemical Properties. Oxygen possesses more extensive 
powers of combination than any other substance. It may be 
made to combine with all the simple substances. For acids 
and alkalies it has little affinity, because these substances 
have already received their proportion of it. Some of its 
combinations with the metals, and with combustibles., are 
very energetic. 

Exp. 1. Let down a pendent candle into ajar of the gas, (Fig. 67.) 
and it will burn with great brilliancy. 



*■ The iron retort is an iron bottle with 
a long neck. After the salt or the man- 
ganese is put into it, it may be placed 
in a furnace, and a lead pipe, as b or a, 
(Fig. 66.) adapted to the mouth, by 
means of a cork, «, a. The cork is first 
perforated by a hot, sharp iron, and en- /^~ T= ^> 
lavged, so as exactly to fit the tube, by a 
round file ; it is then pressed into the 
mouth of the bottle. The other end 
may then be conveyed to any part of 
the pneumatic cistern, or to the gas- 
ometers. This is the simplest mode of 
connecting apparatus together ; and it 
may be done either with glass or lead 
tubes. 



Fig. 6G 




■ 



140 



Oxygen. — Theory 




Fig. 




6D. 



Exp. 2. Blow out a candle, leaving a red wick, Fig. 67. 
and let it down into a jar of the gas, when it will be 
relighted with a slight explosion. This process may 
be repeated several times in rapid succession with 
the same jar of gas. 

Exp. 3. If a bit of lighted phosphorus, in a capsule, 
be immersed in this gas, (Fig. 68,) it will burn with 
great energy and intense brilliancy. Substitute for 
the phosphorus a small ball formed of turnings of 
zinc, in which a small bit of phosphorus is enclosed, 
and set fire to the phosphorus, as before. The zinc 
will be inflamed, and burn with a beautiful white 
light. Metallic arsenic, moistened with spirits of 
turpentine, and various other metals, in fine powder, 
may be burned in a similar maimer. Homberg's 
pyrophorus flashes spontaneously, like inflamed gun- 
powder. 

Exp. 4. If iron wire, with a small lighted match 
attached to one end, be let down into a tubulated 
bell glass of oxygen, it will burn rapidly ; and if a 
watch-spring be used, (Fig. 69,) the bell glass will 
be filled with beautiful star-shaped scintillations. 

Exp. 5. Or, let a stream of oxygen upon ignited 
charcoal, upon which is placed the end of a watch- 
spring ; it will burn with great brilliancy, and throw out 
immense numbers of the star-shaped scintillations. 

Exp. 6. Put a small bit of phosphorus into a test- 
glass tube, and fill the tube with warm water, so as to 
melt the phosphorus. Direct, now, a stream of oxygen 
gas from the gas bag. or a bladder, to which a tube 
is attached, upon the phosphorus. A brilliant combus- 
tion will be produced under water. 

All substances, by combustion in oxygen, increase in weight, 
in the proportion of about A- of a grain for every cubic foot of gas 

Exp. 7. Fill the bowl of a tobacco-pipe with iron wire, coiled in a 
spiral form, and carefully weighed; heat the bowl of the pipe red "hot 
and then attach the pipe to a bladder filled with oxygen gas. By 
forcing a stream of the gas through the pipe, the iron will burn, and 
will be found, when weighed, to be heavier than before. When com. 
pletely oxidized, 100 parts of iron will gain an addition of about 30. 

Theory. In these experiments, the oxygen combines with 
the combustible substance, and forms a compound, which, 
being now oxidized, is incapable of further combustion. In 
case of the iron, an oxide is formed, the weight of which is 
exactly equal to that of the iron and the oxygen together. In 
case of the phosphorus, an acid is formed, which is absorbed 
by water, if present, or appears as a fine powder. The heat 
and light appear to arise from the condensation of the gas.* 

* In the case of combustion, the common opinion that the matter ia 
destroyed, is erroneous. If the products are collected, they will be 
found equal in weight to the substances burned. It is a universal law 
that no particle of matter is annihilated. 




Chlorine. 14 1 

The combination of oxygen with other substances is called 
; oxygenation, and if the compound be an oxide, oxidation* 
! Oxygen is slightly absorbed by several substances; 100 cubic 

"riches of water absorb three or four cubic inches of the gas. 
The relation of oxygen to animal life is very intimate and 

important. It is the only substance which will, for any length 
ii of time, support respiration. No animal can live without it. 
| ; If confined in gases destitute of oxygen, death is the certain 

consequence. A few years since, 148 persons were confined 
j 1 in a prison called ' Black Hole,' in Calcutta, for a night, and, 
j although there were two windows open in the west end of the 
i building, only twenty-three were found alive in the morning. 
Pure oxygen gas is generally destructive to animal life. 
• The animal confined in it lives too fast ; breathing becomes 

difficult, and if it remain for any time, death will ensue. 
If the quantity be small, it will support life longer than the 

same quantity of common air. A bird will live five or six 
I times as long in a Hew gallons of oxygen as in the same 
1 quantity of confined air. In order to its most salutary 
| effects, it should be diluted with nitrogen, as we find it in the 

atmosphere. The Creator has, in this respect, adapted it to the 
j support of life, as any thing which destroys the relation thus 

established, renders it deleterious to the animal constitution. 

Uses. Oxygen has been used with good results in certain 

, diseases, such as paralysis of the thorax, and general debility. 

Its effect upon the blood is to change it from dark red to a 

bright vermilion. 

Sect. 2. Chlorine. 

c;-™u m *w„ {bv vol. 100. « n C 2.47 Air =1. 

Symb.Cl. Equiv.J u ivgL35A2 . S P" Gr - { 35.42 Hyd. =1. 

History. Chlorine was discovered by Scheele in 1774, 
1 and described under the name of dephlogisticated marine 

* It has been customary with many to call oxygen, and some other 

kindred uibstances, " supporters of combustion" while the substances 

I with wh ch they combine are called combustibles. But the supporters of 

j combusl .on and the combustibles are alike essential to the combustion, 

' end- bo? a a r e consumed in the process. Indeed, if the latter be in ex- 



142 Chlorine. — History 

azid. The French chemists called it oxygenized muriatic 
acid, afterwards contracted to oxy-muriatic acid. This name 
implied a theory of its composition, suggested by Berthollet, 
that it was a compound of muriatic acid and oxygen. Gay 
Lussac and Thenard, in 1809, first suggested that it might 
be a simple substance. Sir II. Davy, after subjecting it to 
the most powerful decomposing agents, without in the least 
affecting its character, denied its compound nature, and 
maintained that, according to the true logic of chemistry, it 
should be regarded as a simple body. The views of Davy 
were for a long time combated. Drs. Murray and Thomp- 
son in England, and Berthollet, Gay Lussac, and Thenard in 
France, engaged with great warmth in the controversy. 
But the name chlorine, suggested by Davy from a Greek 
word * signifying green, not implying any theory as to its 
nature, came gradually into use, and the contest subsided. 
It is now universally regarded as a simple substance. 

The introduction of chlorine into the class of simple 
bodies changed entirely the views of chemists relative to the 
theory of combustion. Previous to the discovery of oxygen, 
the Stahlian theory of combustion was generally adopted. 
According to this theory, combustion was the escape from 
combustibles of a certain principle called phlogiston, which 
pervaded most bodies. Soon after the discovery of oxygen, 
Lavoisier made an attack upon the phlogistic or Stahlian 
theory, and proved that combustion was produced by the 
union of oxygen with some combustible body. But when the 
properties of chlorine were investigated, and it was viewed as 
a simple substance, it was found to produce all the phenomena 
of combustion. Hence the theory of Lavoisier, that combus- 
tion was owing to the union of oxygen with a combustible, was 
extended ; and the phenomena of combustion are not referred 
to any more specific cause than intensity of chemical action. 

Natural History. Chlorine is one of the constituents of 
common salt, and therefore exists in the ocean in large quan- 
tity. Other compounds in the mineral kingdom are numerous. 

cess, a portion of it will remain, while the former will be entirely con- 
sumed. Generally, the supporter of combustion, as it is called, is a gas 
which envelops the combustible ; but there is no scientific distinction 
* Xlwqog. 



Physical and Chemical Properties. 143 

Pj'occsscs. 1. It may be_ obtained in the form of a gas, by 
the action of hydrochloric acid upon the binoxide of manga- 
nese. Take the latter, finely powdered, in a retort, and pour 
on twice its weight of concentrated hydrochloric acid. Collect 
the gas over the cistern in inverted bottles containino- warm 
water, or, more conveniently, over a small cistern of warm 
water. The water should be raised to 70° or 80° Fahr., as 
cold water rapidly absorbs the gas. Apply a moderate heat ; 
and, when the 'bottles are filled, they should be stopped with 
ground glass stoppers smeared with tallow. 

Theory. In this process, the binoxide of manganese is 
decomposed into protoxide and oxygen. A part of the acid 
combines with the protoxide, and another is decomposed, its 
hydrogen uniting with the oxygen, and forming water, and 
the chlorine is set free. In other words, the MnO 2 and HC1 
are converted into MnO -f- HC1, and HO, which remain in 
the retort, and CI, which comes over. 

2. The cheapest mode of obtaining chlorine is the follow- 
ing : — Put eight ounces of common salt, with three ounces 
of pulverized peroxide of manganese, and five ounces of 
sulphuric acid, diluted with equal weights of water, into a 
Florence flask or retort, and apply heat as before. The 
MnO 2 , Na + Cl, and 2S0 3 are converted into MnO + 
SO 3 , NaO + SO 3 , an d ci. 

Physical Properties. Chlorine gas is of a greenish-yellow 
color; has an astringent taste, and a disagreeable odor; is a 
non-conductor of electricity, and goes to the positive pole in 
the galvanic circuit. By the pressure of four atmospheres, 
or 69 lbs. to the square inch, it is condensed into a yellow 
liquid, and into a solid by the reduction of the temperature 
below 32°.* 100 cubic inches of this gas at 60° Fahr., and 
30 baiometer, weigh 76.59S8 grains. 

Chemical Properties. Chlorine unites with many sub- 
stances with great energy, producing combustion; but its 
range of affinity is more limited than that of oxygen. 

* Mr. Faraday succeeded in condensing it in a bent tube, sealed 
hermetically. The pressure is produced by the accumulation of the gag 
evolved by the affinities between the materials in the short end of the 
tube. The experiment is attended with the hazard of breaking the tube, 
aad should not be attempted, unless t&e hand* and face are orotected 



844 Chlorine, 

Exp. I. If a small lighted taper be immersed in a jar of the gas, the 
taper will burn for a short time with a small red flame, evolving large 
quantities of smoke, and then go out. The reason is, that the flame is 
mostly composed of carbon and hydrogen; the chlorine unites with the 
hydrogen, but not with the carbon ; the latter is therefore precipitated 
in the form of smoke, and soon puts the light out. 
''Exp. 2. Into a tall glass vessel, filled with chlorine, throw finely- 
pulverized antimony ; the metal will burn as it falls through'the gas.. 

Exp. 3. A rag wet with oil of turpentine will instantly be inflamed, 
when immersed in the gas. 

Exp. 4. Introduce phosphorus into ajar of chlorine; the phosphorus 
will soon ignite, and burn with a pale-green flame. 

Exp. 5. Instead of the phosphorus, drop in a few drops of liquid 
ammonia; the ammonia will be decomposed; a flash and a white 
smoke will be instantly produced. 

Several other metals and combustibles combine with chlo- 
rine with such energy as to exhibit the phenomena of com- 
bustion. 

Chlorine is .readily absorbed by water. Recently-boiled 

water, when cold, absorbs twice its bulk, but gives it off when 

heated. 

Exp. Into a jar furnished with a well-fitted glass stopper, and filled 
with cold water, let up chlorine gas enough to displace half the water; 
stop it tight, and shake it, and most of the gas will be absorbed by the 
water. Open the jar under more cold water, which will rush into it to 
fill the vacuum occasioned by the absorption of the chlorine ; then re- 
peat the process once or twice, and the water will be saturated with 
chlorine, and possess most of its properties. If the water in this ex- 
periment be at the temperature of 32° Fahr., the chlorine will form a 
definite solid compound with it, in yellow crystals, which will be seen 
on the sides of the jar. The crystals are composed of 35.42 or 1 atom 
of chlorine, and 90 or 10 atoms of water. 

Chlorine forms with hydrogen, if the vapor of water be 
present, a mixture which explodes violently when exposed 
to the direct rays of the sun, or even in a bright day with- 
out such exposure, the violet ray produces this effect.* 

Exp. Mix, in a dark place, equal measures of hydrogen and chlorine. 
Expose the mixture to the light of day, and a slow action will take 
place. Cover the glass with a black cloth, to which a string is attached, 
and place the vessel in the direct rays of the sun. Remove the cloth 
by means of the string, taking care to have some object, as a door, be- 
tween you and the receiver; as soon as the rays of light strike the 
mixture, a violent explosion will occur, and an acid compound will 
be formed. 

Chlorine possesses remarkable bleaching properties. 
Exp. 1. Immerse in the gas strips of calico, flowers, etc., and they 
will be bleached in a short time ; or the saturated water mav be used, 

* Chlorine thus appears to exist in t\ ro states, called Allotropism. Prepared in 
the dark, it is indifferent to hydrogen, but light gives it a most powerful affinity for it. 



Uses of Chlorine. 145 

Exp. 2. Pour some of the saturated water into a small quantity of 
ink, and the color will be discharged; or put into it. some writing, 
which will become invisible, but will be restored if immersed in a solu- 
tion of prussiate of potassa. Printers' ink will not be affected ; an^ 
hence chlorine water may be used for removing blots from books. 

Chlorine is not an acid; for it does not redden vegetable 
purples, and it combines directly in definite proportions with 
the metals, which is not true of any acid. It is not alkaline. 

Chlorine is very destructive to animal life. A few bubbles 
of gas, in the atmosphere of a room, will bring on coughing. 
Half a gill undiluted in the lungs would cause death. If 
diluted largely with air, it irritates the throat and lungs, and 
if pure, destroys their texture. Pelletier is said to have fallen 
a victim to its effects. The antidote is ammonia. 

Uses. 1. The bleaching properties of chlorine are turned 
to great account in the art of bleaching. Both the gas and 
the water saturated with it were f employed as early as 1784-5 
for bleaching cloths ; but it proved injurious to the workmen. 
In 1789, the gas was condensed in a solution of pearl ashes, 
and went by the name of " Liquid javelle." But this sub- 
stance soon gave place to Mr. Tennant's preparation of the 
chloride of lime, in 1798. Since that period, most of the 
bleaching of cotton and linen goods has been effected by this 
substance. The articles to be bleached are first steeped in hot 
water, boiled in a weak alkali, and then immersed in a solu 
tion of the chloride of lime. They are next taken out, and 
washed in water ; sometimes diluted sulphuric acid is applied 
to increase their whiteness ; and, finally, they are boiled in 
pearlashes and soap, to render them free from the odor of 
chlorine. Chloride of soda, magnesia, and potassa, are some- 
times used, but they are more expensive.* 

Theory. The theory of this process, perhaps, would be better un- 
derstood after learning the composition of water; but it can be given 



* The advantages of this mode of bleaching, over the one formerly 
employed, are very great. By the old method, large fields in the 
vicinity of every manufactory were devoted to the purpose of spread- 
ing the cloths. These fields are now devoted to agriculture. It re- 
quired also several weeks, and even months, to complete a process 
which may now be performed in as many days. In the former case, 
they were dependent upon the light of the sun and fair weather; 
in the latter, they are independent of the weather, and of the seasons 
of the year. 

7 



146 Chlorine and Oxygen 

here with a little explanation. Water is necessary to the bleaching 
effects of chlorine. It is composed of oxygen and hydrogen. The 
chlorine, having a strong affinity for the hydrogen, decomposes the 
water, and leaves the oxygen to combine with the coloring matter. 
The coloring matter may also contain hydrogen, and thus be directly 
decomposed by the chlorine. The coloring matter is rendered soluble 
by combination with oxygen, and is removed by the alkali. The pro- 
cess of bleaching by chlorine is but one out of many useful con- 
tributions of science to art. 

2. Another use of chlorine arises from its disinfecting 
agency. It seizes hold of every species of animal and vege- 
table effluvia, and decomposes them. Hence its utility in 
contagious diseases. The chloride of lime is used for this 
purpose. Moisten the dry chloride with water, and place it 
in the infected apartment, which will soon be purified. It is 
thus very useful for dissecting-rooms, for cleaning drains, 
sewers, vessels, and even the atmosphere, when charged with 
miasma. Its use in medicine is mostly confined to the puri- 
fication of apartments of the sick. Tne chloride of soda is, 
however, used in certain cases of inflammation, such as 
ulcers, mortification, and cutaneous diseases. It is also used 
as a wash for the teeth.* The compounds of chlorine with 
the metals are called chlorides. 



Chlorine and Oxygen. 

The compounds of chlorine and oxygen are held together 
by very feeble affinities, and are never met with in nature. 
They cannot be made to combine directly, unless they are in 
the nascent state, that is, at the instant of their formation. 

Hypochlorous Acid. Symb. CI + O or CIO. Equiv. 35.42 + 
8=43.42. Sp. gr. 3.0212. It was discovered by H. Davy, 
in 1811, and called euchlorine from its being of a brighter 
color than chlorine. 

Preparation Put two parts of the chlorate of potassa and cne of 
hydrochloric acid into a retort, and apply the heat of water under 
200° Fahr. Collect over mercury ; or it may be more conveniently 
prepared for experiment by placing the materials in a flask, 



* So many and great are the advantages of cleanliness and pure air, 
that chloride of lime should be kept in every family, especially in cities 
and large towns ; but an apartment in which it has been used should 
be thoroughly ventilated before it is again occupied, or weak lungs may 
be seriously injured. 



Clilorine and Oxygen. 



147 



I (Fig. 70,) connected by a glass tube, bent twice 
at right angles, with a tall receiver, b. Apply 
heat as before ; the gas, being heavier than the 
air. will displace it, and fill the receiver.* 

Tlieory. The hydrochloric acid and the chlo- 
ric acid in the chlorate of potassa mutually decom- 
pose each other, and the results are water and the 
hypochlorous acid. 2 equiv. HC1, and one of 
KO-f-CIO 5 , are converted into KO, 2 Aq, and 
SCIO. 



Fig. 70. 




If the gas be collected over mercury, the chlorine unites 
with the mercury, and the acid remains in a pure state. 

Properties. Greenish yellow color, more brilliant than 
chlorine ; odor like burned sugar ; absorbed rapidly by water, 
and gives to it an orange color ; bleaches vegetable sub- 
stances ; gives vegetable blues a red tint before destroying 
them ; . does not unite with alkalies, and hence has been con- 
sidered as a protoxide of chlorine ; highly explosive, the heat 
of the hand being sufficient often to explode it. Many sub- 
stances take fire in it spontaneously. 

Exp. A rag dipped in spirits of turpentine will kindle in it with a 
slight explosion. 

Exp. Phosphorus explodes in it spontaneously. Fifty measures of 
this gas, and eighty of hydrogen, form an explosive mixture. 

Chlorous Acid. Symb. Cl + 40, or CIO 4 . Equiv. 35.42 
-f 32 = 67.42. Sp. gr. 2.3374. Discovered by Davy, in 
1815, and soon after by Count Stadion, of Vienna, and has 
been heretofore described as peroxide of chlorine. 

Preparation. Make a paste of strong sulphuric acid and chlorate of 
potassa; put it into a retort, and apply the heat of warm water under 
212° Fahr. Collect over mercury, or as in Fig. 64. For the purposes 
of experiment, take a wine or champagne glass, and put into it'a few 
grains of chlorate of potassa; then pour on sulphuric acid; the gas will 
soon fill the glass. As the gas often explodes spontaneously, this is the 
safest mode of collecting it. The preceding compound may be formed 
in the same way. 

Properties. Color, bright orange-green, richer than the 
preceding compound ; aromatic odor ; is absorbed rapidly by 
water, and gives it its peculiar color; bleaches powerfully, 
and is more explosive than hypochlorous acid. 

Exp. Put a bit. of phosphorus into a wine glass filled with the gas. 
It will instantl}' ignite, with a slight explosion. % 

Chloric Acid. Symb. CI + 50, or CIO 5 . Equiv. 3||£ + 
40 — 75.42. It was first noticed by Mr. Chenevix, and ob- 
tained in a separate state by Gay Lussac. 

* To avoid the danger of explosion, a wine-glass had better be used, 
*s directed for chlorous acid. 



1 48 Iodine. 

Preparation. To a dilute solution of chlorate of baryta add dilute 
sulphuric acid sufficient to combine with the baryta. Pure chloric acid 
will remain after the baryta subsides. 

Theory. The sulphuric acid has a stronger affinity for baryta than 
the chloric acid with which it has combined, decomposes it, and leaves 
the chloric acid. 

Properties. Sour to the taste; reddens vegetable blue 
colors, but possesses no bleaching properties, by which it is 
distinguished from the preceding compounds. It may be 
concentrated by gentle heat into an oily liquid of a yellow 
tint, emitting the odor of nitric acid. In this state, it sets 
fire to paper and dry organic matter, and converts alcohol 
into acetic acid. 

Perchloric Acid. Symb. CI + 70 or CIO?. Equiv. 35.42 
-f- 56 = 91.42. Sp. gr. 1.65, water = 1. It was first described 
by Count Stadion, of Vienna. 

Process. It may be obtained by heating- a mixture of 1 part of water, 
3 of sulphuric acid, and 5 of perchlorate of potassa. At a temperature 
of 284°, white vapors arise in the receiver, which are soon condensed into 
a colorless liquid. By admixture with sulphuric acid, and distillation, 
it crystallizes in elongated prisms. 

It is a very stable compound ; absorbs moisture from the 
air powerfully, and boils at 392° Fa.hr. When thrown into 
water, it hisses like red-hot iron. 



Sect. 3. Iodine. 

u u . v • C by vol. 100. « n C 4.948 Water = 1. 

bymb. I. Eqmv. J J wgt 126 3 Sp. Gr. J g m AJr = 1 

History. Iodine was discovered in 1812, by a manu- 
facturer of saltpetre — M. Courtois, of Paris. The substance 
in which it was first noticed, was the residual liquor after the 
preparation of soda from the ashes of sea-weeds. This dark- 
colored liquor possessed the peculiar property of powerfully 
corroding metallic vessels ; on the application of sulphuric 
acid, he noticed that it threw down a dark-colored substance, 
which was converted into a violet-colored vapor on the ap- 
plication of heat. This attracted his attention, and he gave 
some of it to M. Clement, who, in 1813, described it as a 
new body. Gay Lussac and Davy soon after proved it to be 
a simple non-metallic substance, analogous to chlorine. Tho 



Physical Properties. 149 

name iodine is derived from a Greek word,* significant of 
the beautiful violet color of its vapor. 

Natural History. Iodine exists in nature but in small 
quantities. It is found mostly in sea-weeds, in sponges, in 
the oyster and some other mollusca, in many salt and mineral 
springs, both in Europe and America. Vauquelin found it in 
combination with silver ; marine animals and plants derive it 
from sea-water. Most of the iodine of commerce is obtained 
from the impure carbonate of soda, called help. This is 
nothing but the ashes of sea-weed, great quantities of which 
are prepared on the shores of Scotland. Iodine exists, in 
combination with sodium and potassium, in the liquor which 
is left after the carbonate of soda crystallizes. 

Process. Iodine may be obtained by lixiviating the pow- 
dered kelp in cold water. Evaporate the lye till the car- 
bonate of soda crystallizes; take the residual liquor, and 
evaporate it to dryness; pour on to this J its weight of suL 
phuric acid ; it may then be put into a common retort, to 
which is attached a globe receiver, and the retort heated; 
violet-colored fumes will soon arise, and be condensed in 
the receiver, in the form of opaque crystals, of a metallic 
lustre. These are to be washed in water, and dried on a 
filter of unglazed paper. 

Physical Properties. Iodine, at the common temperature, 
is a soft, pliable, opaque solid, of a bluish-black color, and 
of a metallic lustre. It is generally found in small crystalline 
scales, resembling micaceous iron ore, or the scales from a 
smite's forge. But it may be made to crystallize in large 
rhomboidal plates, whose primary form is a rhombic^ octohe- 
dron, by saturating hot alcohol, or hydriodic acid, with it, 
and evaporating in the open air. It is very acrid to the 
taste, and has the odor of chlorine. Like O and CI, it is a 
non-conductor of electricity, and goes to the positive pole in 
the galvanic circuit. It acts as a powerful poison to the 
animal system ; fuses at 225°, and boils at 347° Fahr. If 
moisture be present, it volatilizes at the common temperature, 



Judrjg, 



150 Iodine 

and sublimes rapidly under 212°. The rich violet vapor of 

iodine is remarkably dense, more than eight times as heavy as 

air. One hundred cubic inches would weigh 269.8638 grs. 

Exp. This vapor may be shown by putting a. few grains of the 
iodine into a glass flask, and applying a gentle heat. 

Chemical Properties. Iodine has an extensive range of 

affinity. Like chlorine, it destroys vegetable colors, though 

in a less degree, and, like* oxygen and chlorine, it unites 

directly with the metals and with non-metallic combustibles 

with great energy. 

Exp. Drop a bit of phosphorus upon a few grains of iodine, con- 
tained in a wine-glass, and it will be instantly inflamed. 

The compounds thus formed resemble those of oxygen and 
chlorine. It has little affinity for metallic oxides. It is not 
inflammable, but a supporter of combustion. The im- 
ponderables have no effect to change its character, and hence 
it is regarded as a simple body. It is largely soluble in 
alcohol, and but sparingly soluble in water, requiring seven 
thousand times its weight of water for solution. 

Tests. Starch is a very delicate test of iodine. It gives to the solu- 
tion a deep blue color. A liquid containing ^-^Vo"??" part of its weight 
of iodine, receives a blue tinge from a solution of starch. 

Iodine is sometimes adulterated with black lead. This may be de- 
tected by dissolving it in alcohol, when the lead will not be held in 
solution. 

Uses. Used in medicine in the form of a hydriodate of 
potassa, for certain glandular diseases. The goitre is a kind 
of wen growing from the neck, which is very common in 
Switzerland, in the treatment of which iodine has been of 
great service. 

Its vapor is irritating to the lungs, and produces copious 
secretions in the eyes and nostrils. The compounds of 
iodine with non-metallic combustibles are termed iodurets : 
its compounds with the metals, iodides. 

Iodine forms with oxygen three, perhaps four compounds : 

1. Oxide of iodine, ) osition unknown 

2. lodous acid,. ) L 

3. Iodic acid, 1 eq. 1, 126.3+5 eq. 0,40 = 166.3 eq 
Symb. I + SO or IO 5 . 

4. Periodic acid, 1 eq. I, 126.3 + 7 eq. O, 56=182.3 
Symb. I + 70 or IO 7 . 



Bromine. 151 

The first two compounds, oxide of iodine and iodous acid, 
are yet doubtful. The first is described by M. Sementmi, of 
Naples, and the second by Mitscherlich. The oxide is a 
yellow solid, and the acid a similar liquid, but their properties 
have not been examined. 

Iodic Acid was discovered by Davy and Gay Lussac about 
the same time. Davy, who first obtained it in a pure state, 
called it oxiodine. 

Preparation. When iodine is brought in contact with the hypochlo- 
ious acid, two compounds are formed. The one is a volatile orange- 
colored substance, chloride of iodine, and the other a white solid, which 
is iodic acid. Apply heat to expel the chloride, and the iodic acid re- 
mains in a pure state. (See Turner, for other processes.) In this 
Btate, it is anhydrous iodic acid, that is, destitute of water. 

Properties. It exists as a white, semi-transparent, crystal- 
line solid, of a strong, astringent, sour taste, and no odor; 
fuses at 500° Fahr., and is resolved into oxygen and iodine. 

It is soluble in water, with which it combines, and forms 
hydrous iodic acid ; deliquesces in moist air ; reddens vege- 
table blues, and finally destroys them. With charcoal, sul- 
phur, sugar, and similar combustibles, it forms detonating 
mixtures. 

Periodic Acid was discovered by Ammermuller and Mag- 
nus, and is obtained from the periodate of silver, by adding 
cold water. It has decided acid properties, and is analogous 
in composition to perchloric acid. 

Chloriodic Acid was discovered by Davy and Gay Lussac. 
It may be formed by the direct union of chlorine and iodine. 
[f the iodine is fully saturated with chlorine, it forms a yellow 
solid ; but if the iodine is in excess, the color is a reddish 
orange. It is easily fused, and converted into vapor ; deli- 
quesces in the air ; forms a colorless solution in water ; very 
sour to the taste ; reddens vegetable blues, and finally de- 
stroys them; does not unite with alkalies, and hence has 
been considered a chloride of iodine. 

Souberaine has lately distinguished a compound of 3 eq. 
of chlorine and 1 of iodine. 

Sect. 4. Bromine. 

Symb. Br. Equiv. J ' wgt> ?g 4 Sp. gr. J 5 m7 Aif ^ % 

History. Bromine was discovered in 1826, by M. Balard, 
a young French chemist, of montpelier, who named ilmuride, 



152 Bromine. 

because obtained from the sea ; but, in order to correspond 
with chlorine and iodine, it was called bromine, from a Greek 
word,* signifying rank odor. 

Natural History. It exists in nature in very small quan- 
tities. It 13 found in sea-water and marine plants, combined 
with sodium and magnesium. It is found in every sea whose 
waters have been tested for it, and in many mineral and salt 
springs. 

Process. It is obtained by passing a current of chlorine 
gas through the bittern of sea-water, and agitating the liquor 
with a portion of sulphuric ether. The ether dissolves the 
bromine, from which it receives a beautiful hyacinth-red tint, 
and, on standing, rises to the surface. Agitate this solution 
with caustic potassa, and the bromide of potassium and bro- 
mate of potassa will be formed. Evaporate the liquor, and 
the bromide of potassium will be left, from which the bromine 
may be distilled. 

Physical Properties. Bromine, at common temperatures, 
is a deep reddish-brown colored liquor, of a disagreeable odor 
and caustic taste ; and, like oxygen, chlorine, and iodine, is a 
non-conductor of electricity, and a negative electric ; boils at 
116.5° Fahr., and congeals at -4° Fahr. into a brittle solid. 
It volatilizes at the common temperature and pressure. 

Exp. This may be shown by pouring a few drops of the liquid into 
a glass flask; it will soon be converted into a beautiful vapor, some- 
what resembling the vapor of iodine, having a density of 5.54. 100 
cubic inches at 00° Fahr. should weigh 167.5158 grains. 

Chemical Properties. Its chemical properties are very 
analogous to those of chlorine and iodine. It readily bleaches 
iitmus paper, and discharges the blue color of indigo. A 
lighted taper burns for a few moments in the vapor of bro- 
mine, with a flame green at its base and red at the top, an<? 
is then extinguished. 

Bromine unites with great energy with many combustibles. 

Exp. Pour a few drops of bromine into a strong wine-glass, and then 
pour upon it tin or antimony, in fine powder, from a glass fastened tc 



* Bqwpoq. 



Fluorine. 153 

the end of a long rod ; the metals will be instantly inflamed. If potas- 
sium be used, it will cause a violent explosion. 

Bromine is soluble in water, alcohol, and ether ; the latter 
is the best solvent. With water at 32° F., it forms a hydrate, 
in crystals of a fine red color. It gives to a solution of starch 
an orange color. Chlorine will displace it from all its com- 
binations with hydrogen. It acts powerfully upon the animal 
system, and is very poisonous ; a single drop upon the beak 
of a bird, destroys it instantly. 

Bromic Acid (Symb. Br+50 or BrO 5 . Equiv. 78.4 + 
40 r= 118.4,) may be obtained by pouring sulphuric acid 
upon a dilute solution of bromate of baryta, and evaporating 
the solution. 

Properties. It has scarcely any odor, acrid to the taste, 
though not corrosive. It first reddens litmus paper, and then 
destroys the color. 

Chloride of Bromine may be formed by transmitting a current of 
chlorine through bromine, and condensing the disengaged vapors by 
a freezing mixture. It is a volatile liquid, of a reddish-yellow color, 
less brilliant than bromine. Its vapor is a deep yellow, taste very dis- 
agreeable, and odor penetrating, causing a discharge of tears from the 
eyes. Soluble in water which possesses bleaching properties. 

Bromides of Iodine. Bromine and iodine unite and form two com 
pounds. 

The proto-bromide is a solid easily converted by heat into a reddish- 
brown vapor, which, on cooling, is condensed into crystals of the same 
color, and of a form resembling fern leaves. By the addition of bro- 
mine to these crystals, they are converted into a liquid resembling a 
strong solution of iodine and hydriodic acid; but the nature of it is not 
satisfactorily established. 



Sect. 5. Fluorine 
Symb. F. Equiv. 18.68, eq. vol. 100. 

Fluorine is a name applied to a substance which has not 
as yet been obtained in a simple state. It is inferred from 
the nature of its compounds to be similar to oxygen, chlorine, 
bromine, and iodine. It has a strong affinity for hydrogen 
and the metals. 

Natural History. It exists abundantly in nature, in fluor- 
spar combined with calcium, {fluoride of calcium.) Baudri- 

7* 



154 



Hydrogen. 



mont is said to have obtained it, mixed with hydrofluoric and 
finosilicic acid gases, by treating a mixture of fluoride of cal- 
cium and peroxide of manganese with strong sulphuric acid 
It appears to be a gaseous body, similar to chlorine. 



Symb. H. Equiv. 



Sect. 6. Hydrogen. 

by vol. 100. g ( 



0.0689 Air 
l. Hyd 



History. The name hydrogen is formed from two Greek 
words,* and means a generator of water. It was known for 
many centuries, but was first distinctly described by Mr. Cav- 
endish, in 1776. Nine years previous, Dr. Black discovered 
carbonic acid gas, which was the first gas discovered, except 
the atmosphere, and hydrogen was the second. 

Natural History. Hydrogen is a very abundant substance. 
It forms -£- part by weight of water. Its chief repository, 
therefore, is the ocean ; but it is widely disseminated through 
the animal, vegetable, and mineral kingdoms. It is the basis 
of most liquids. 

Processes. I. Water is always employed for obtaining 
hydrogen. It is composed of oxygen and hydrogen, and the 
object is to decompose it by presenting some substance, with 
which the oxygen will combine, and leave the hydrogen to 
escape in the form of a gas. Iron is such a substance, and 
will decompose the water slowly at common temperatures ; 
the oxygen combining with it, and forming the well-known 
substance called iron rust. Bat if the temperature of the iron 
be raised to 1000° 

Fahr., and the va- Ms. 71. 

por of water passed 
over it, it will de- 
compose it more 
rapidly. For this 
purpose, clean iron 
turnings, or bright 
iron wire, are pla- 
ced in the centre 




r YSt»Q and ytvvao). 



Processes — Theory. 155 

of a gun-barrel, C, (Fig. 71,) open at both ends, and passed 
through a furnace, b. Into one end the vapor of water is 
made to pass from the retort a, and the other end is con- 
nected by a lead pipe with the pneumatic cistern. As the 
vapor passes over the iron, its oxygen combines with it, and 
its hydrogen passes over into the receiver A.* 

2. It is more conveniently obtained by putting small 
pieces of zinc,f or iron turnings, into a glass or lead retort, 
and pouring on one part of sulphuric acid, diluted with four 
parts by weight of water, and collecting as above. 

Theory. In this process, the oxygen of the water unites 
with the zinc, and forms oxide of zinc, which combines with 
the acid, while the hydrogen of the water escapes. This was 
formerly supposed to be a case of what was called disposing 
affinity, in which the acid disposed the oxygen and zinc to 
unite, that it might combine with the compound ; for it has 
no affinity for them separately. This is sufficiently absurd. 
The process commences with zinc and water alone, without 
the aid of the acid, and is immediately arrested by the forma- 
tion of a coat of oxide of zinc, which protects the zinc from 
the action of the water. The acid dissolves away this coat- 
ing; of oxide as fast as formed, and thus the action of the 
metal and the water is uninterrupted. But the change is 
best explained by referring it to galvanic action. 

For every9grs. of water which are decomposed, 1 of hydro- 
gen is set free. 8 grs. of oxygen unite with 28 of iron, forming 
56 of the protoxide of iron. 1 oz. of iron yields 782 cubic 
inches, and 1 oz. of zinc 676 cubic inches, of hydrogen. 

Impurities. The hydrogen, obtained in these processes, is not quite 
pure. That from the iron contains a volatile oil, produced by the hy- 
drogen and the carbon in the iron; this may be removed by passing 
tbe~gas through alcohol. When zinc is employed, (and it is generally 



* If the water and the iron are weighed before the experiment, and 
the iron and the hydrogen after it, the increase in the weight of iron 
and the weight of the hydrogen is just equal to that of the water. 
In this way tlie exact composition of water is determined analytically, 
and is found to be 8 parts of. oxygen to 1 of hydrogen, and 1 vol. of the 
former to 2 of the latter. 

t The -iiic may be conveniently prepared by pouring a stream of the 
mel ♦*..'! metal into cold water . 



150 



Hydrogen. — Physical Properties. 



preferred,) the impurities result from the sulphur which it generally 
contains — hydrosulphuric acid is formed, and there are also traces of 
metallic zinc and carbureted hydrogen. These, except the last, may 
be removed by passing the hydrogen through pure potassa. When 
hydrogen of great purity is required, distilled zinc should be used. 

Physical Properties. Hydrogen gas is colorless, tasteless, 
and, when perfectly pure, inodorous. But as it is generally 
obtained, it has a fetid odor, arising from the oily matter 
which it contains, and the hydrosulphuric acid. It is a pow- 
erful refractor of light, and has never been condensed to a 
liquid. 

It is the lightest body in nature. It is sixteen times lighter 
than oxygen, 36 times lighter than chlorine, 200,000 times 
lighter than mercury, and 300 000 times lighter than 
platinum ! 

Exp. Fill a gas bag with Fig. 72, 

hydrogen,* (Fig. 72 ;) con- 
nect it with a bubble-pipe, 
and inflate soap bubbles with 
the gas; they will ascend 
rapidly, being forced up by 
the superior weight of the 
air. Or, if a j ar of hydrogen 
be removed from the cistern, 
and inverted in the open air, 
the gas will immediately escape. 

In consequence of its extreme lightness, hydrogen is used 
for filling balloons. 




* The method of filling gas bags with 
gases from the pneumatic cistern, is repre- 
sented in Fig. 73, b is the cistern contain- 
ing water ; the receiver has a stop-cock in 
its top, upon which another stop-cock, C, 
connected with the bag a, may be screw- 
ed, The receiver is filled with gas, and, 
the stop-cocks being both open, is pressed 
down into the well, and the water presses 
the gas into the bag. Then, by closing 
both stop-cocks, the bag may be removed 
from the receiver. 



Fig. 73. 




Chemical Properties. 



157 




Aerostation. Roger Bacon first suggested the pos- 
sibility of navigating the air by mechanical contri- 
vances; but nothing of consequence was effected until 
1782. The substance first employed to raise balloons 
was rarefied air, confined in a silk bag. Since the 
discovery of hydrogen, it has been universally em- 
ployed for this purpose. Balloons are made of various 
shapes and capacities. The spherical form (Fig. 74) 
is the best, for the reason that a given quantity of can- 
vass, or silk, made in the form of a sphere, will contain 
more than any other form, and hence offers the least 
resistance to the air. The substance employed for bal- 
loons is either varnished silk or gold-beaters' skin, and 
the size varies from 1 to 40 feet in diameter. They 
are generally covered with a net, n, connected by cords to a small boat, 
c, in which the aeronaut is stationed when he ascends. The hydrogen 
is prepared by putting iron turnings, sulphuric acid, and water, into 
several large casks, and connecting each with the balloon ; the hydrogen 
is then rapidly evolved, and the balloon tied down until ready for use. 

Chemical Properties* Hydrogen has a strong affinity for 
many substances, and the energy of its combinations fre- 
quently produces the phenomena of combustion. 

Hydrogen is a combustible body, but not a supporter of 
combustion. 

Exp. Plunge a lighted taper into an inverted jar of hy- Fig. 75* 
drogen ; the gas will instantly be inflamed at the mouth of 
the jar, and burn with a blue light; but the taper, if wholly 
immersed in the gas, will be extinguished, and relighted 
again when the wick touches the flame. 

Exp. Burn a jet of hydrogen. If the hydrogen be 
forced rapidly through a tube, b, (Fig. 75,) with a small 
orifice, ignited at the orifice, and cylinders of glass, as a, or 
other substances, put over the flame, musical tones will be 
produced. The tones will vary with the size and kind of 
tube. 

Exp. Mix two measures of hydrogen with one of oxy- 
gen, and apply the flame of a candle to a small portion 
confined in an exploding tube, or gas pistol, a, (Fig. 75;) 
there will be a violent explosion. This effect is also pro- 
duced by mixing one part of hydrogen with three of com- 
mon air ; but the explosions are much more violent when 
two vols, of hydrogen and one of oxygen are mixed, and 
ignited with the flame of a candle ; or by the electric 
spark. Soap-bubbles may be formed and exploded as they 
rise. A large bladder, filled with the mixture, may also be 
exploded by piercing it with a sharp wire on the end of a 
long rod, having about it ignited tow. 

Exp. This mixture also explodes when suddenly com- 
pressed by the fire-syringe ; this is owing to the develop- 
ment of its latent caloric, or because the particles are then 
Drought within the sphere of each other's attraction ; but 
.he experiment is hazardous 

* Hydrogen, though it has never been condensed, possesses many of She propajw 
ties of a vuttU. (See page 225.) 



Fig 




158 Hydrogen and Oxygen. 

Theory. The report arises from the collapse of the air, 
and consequent expansion of the vapor of water, produced 
by the liberated caloric at the moment combination takes 
place. The musical tones arise from continued explosions, 
consequent upon the union of the hydrogen with the oxygen 
of the air. 

Exp. IVhen a stream of hydrogen gas is brought in contact zoith 
spongy platinum, it is immediately set on fire. This heat is supposed to 
be due to the condensation of the gas upon the surface of the plati* 
num, by which its latent caloric becomes sensible, and inflames the gas 

This singular fact was discovered by Prof. Doebereiner, of 
Jena, in 1824. The sponge is prepared by dissolving plati- 
num in nitro-muriatic acid, and then precipitating it with 
ammonia, Rhodium and Iridium produce the same effect. 
This property has been applied to the construction of lamps, 
by which light can be easily and conveniently produced. 

Under pressure, the combustion of hydrogen produces a very 
intense heat. 

Exp. Burn a jet of hydrogen, and throw on iron filings ; they will bf 
ignited, and produce beautiful scintillations. One pound of hydroger 
in burning, will develop sufficient heat, according to Dalton, to me** 
320 lbs. of ice. 

Relations to Animals. An animal soon dies when confined 
in it. This is not owing to the noxious properties of the 
hydrogen, since an atmosphere of oxygen and hydrogen will 
support respiration for a considerable time ; " but is due to the 
fact, that it excludes the oxygen, and thus suffocates. An 
atmosphere of oxygen and hydrogen has the singular property 
of producing a most profound sleep. 

Hydrogen and Oxygen. 

Protoxide of Hydrogen, or Water. 1 eq. H 1 -\- 1 eq. O 8 
== T eq. Symb. H + O or Aq. Sp. gr. = 1 

Process. Water is the sole product of the combustion of 
hydrogen gas in common air, or oxygen. This may be shown 
by burning a jet of hydrogen in a large globe receiver ; or, 
what will render the effect more striking, by burning a jet of 
2 vols, of hydrogen to 1 of oxygen, with the compound 
blowpipe : the sides of the receiver will soon become hazy, 
from the deposition of water upon its interior surface ; and if 
the process be continued, large drops will form and run down 
the sides. This fact was first demonstrated by Mr. Caven* 



Physical and Chemical Properties. 159 

dish by burning the gases as above; and the weight of the 
water produced was exactly equal to that of the gases con- 
sumed. 

Physical Properties. These are well known. It is trans- 
parent, colorless, inodorous, and tasteless ; slightly com- 
pressible by a very strong pressure ; elastic ; converted into 
vapor by heat ; boils at 212° F., and congeals at 32° F. It is 
the standard of weight, with which all solid and liquid bodies 
are compared ; its specific gravity is therefore 1. One cubic 
inch weighs 252.458 grs. It is 815 times heavier than the 
atmosphere, which is the standard of weight for gaseous 
bodies. 

Chemical Properties. 1. Water has the power of ab- 
sorbing a great number of gaseous bodies. It always con- 
tains air. 

Exp. This may be shown by placing it under the receiver of an air- 
pump, and exhausting the air, when bubbles of air will rise up through 
the water. 

It is the air contained in water from which fishes obtain 
the oxygen necessary to purify their blood. 

At the mean temperature and pressure, water will absorb, 
according to Henry and Dalton, of 



Carbonic acid gas, . 1 vol. 


Carbonic oxide, 


A 


Sulphur eted hydrogen, 1 " 


Carbureted hydrogen, 


sV 


Nitrous acid, ... 1 " 


Nitrogen, . . . 


rir 


defiant gas, ...'■$■" 


Hydrogen, . . . 


(t 


Oxygen, . . . . -^ « 







But if the gas be passed through the water under great 
pressure, a greater quantity will be absorbed. Carbonic acid 
gas, for example, is absorbed according to the pressure ap- 
p.ied, to an unlimited extent. 

2. Water is one of the most powerful solvents in nature. 
It inters into combination with various bodies ; sometimes in 
indef.nite proportions, as in solutions ; at others in definite pro- 
portions, as in the acids, some of the metallic oxides, and many 
salts, in whose crystallization it is taken up, and m which it 
ts therefore called the water of crystallization. The definite 



160 



Hydrogen and OtygM. 



compounds are called hydrates* The affinity of water foi 
some substances is so strong, that it cannot be entirely 
separated from them without at the same time decomposing 
the substance. 

Composition of Water. This has been Fig. 77. 

accurately determined, both by analysis 
and synthesis. By synthesis, by burning r \ j 

2 vols, of hydrogen and 1 of oxygen, the <?L — ~l^.\ i' 

product is water. Also, by exploding 2 
vols, of hydrogen and one of oxygen, in a 
strong glass tube, or Eudiometer, a, (Fig. 
77,) over mercury, by the electric spark, 
there will be a perfect vacuum produced, 
and the mercury will rise, and fill the tube. 
Instead of inflaming the gases by the 
electric spark, spongy platinum may be 
employed to produce- a combination of 
the oxygen and hydrogen. 

Exp. Take three parts of spongy platinum, one of pipe-play, 
moistened with water, and a small quantity of hydrochlorate of am- 
monia, make it into a small ball, and ignite it, to separate the wate* 
and ammonia. Introduce it, while hot, into the mixture, and the 
oxygen and hydrogen will combine slowly, without explosion. If the 
gases are mixed in the proportions of 1 vol. of oxygen to 2 of hy 
drogen, they will wholly disappear, and water will be the only product 

Water may be decomposed by the galvanic battery, and the 
products are 2 vols, of hydrogen to 1 of oxygen. The same 
results are obtained by passing its vapor over red-hot iion, 
and collecting the products. 

Compound Blowpipe. This apparatus was invented by Dr. 
Hare, in 1804. The best construction for experimental pur- 
poses is the following : A,B, (Fig. 78,) are two cylinders of 
wood or copper open at the top ; c, a, two similar cylinders 
open at the bottom, placed within the others, leaving spaces 
of ^ of an inch in width between them, and passing around 
cylinders of wood which nearly fill them. The spaces i, e, are 
filled with water, and the gases are conducted by a lead pipe 
into c and d, which are the gasometers. As they are filled, 
they are lifted up by the weights. f The tubes h, o, connect 



* The term hydrous is prefixed to substances containing water, and 
anhydrous to those deprived of it. 

t A method for raising and depressing the gasometers has lately 
been devised, which answers abetter purpose than weights. A bar or 



Hydrogen and Oxygen. 
Fig. 78. 



163 




the gasometers with the blowpipe ; the gases are let out by 
means of stop-cocks, d, being filled with oxygen, the gas 
passes in the tube o through the centre of the blowpipe ; c, 
at the same time, being filled with hydrogen, the gas passes in 
the tube h to the side of the blowpipe, and issues at the 
point, so as to encircle the oxygen. By igniting the two 
gases, as they issue from the pipe, the heaj is so intense as to 
melt the most refractory substances. It is only surpassed by 
that from a powerful galvanic battery. In burning the metals 
undsr the blowpipe, an opportunity is afforded for many in- 
teresting and beautiful experiments.* 

Binoxide of Hydrogen. Symb. H -f- SO or HO 2 . Equiv. 1 -f- 1 6 = 17. 
Sp. gr. 1452, water = 1. This singular compound was discovered by 
Thenard in 1818, and is sometimes called oxygenized icater, and peroxide 
of hydrogen. It is formed by the action of hydrochloric acid upon the 
peroxide of barium. 

Properties. The binoxide of hydrogen is a colorless, transparent 
liquid, without odor, caustic to the skin, giving it a white stain, and 
possesses powerful bleaching properties. When heated to 59° Fahr., 
it is decomposed so rapidly as to cause explosion; the same effect is 
also produced by throwing it on to several of the oxides of metals, 
such as the peroxide of silver, lead, mercury, gold, and some others. 



rod of iron is fastened by one end to the centre of the gasometers. 
The other end passes up through the cross-bar S ; on one side of this 
bar are teeth, which lit into a cog-wheel, and the gasometers are raised 
and lowered by a crank attached to the wheel. 

* In experiments with the blowpipe, the hydrogen should first be 
inflamed, and then the oxygen let out gradually, until the substance to 
be melted is fully ignited; the hydrogen may {hen be shut off, and the 
tombustion kept up by oxygen alone. 



162 Hydrogen and Chlorine. 

Hydrogen and Chlorine — Hydrochloric Acid. 

Symb. H + Cl. Eq. by vol. 200, by wgt 35.42-4-1 = . 
36.42. Sp. gr. 18.21 Hyd. = 1, 1.2694 air ='1. 

History. This compound has been long known under the 
Raines of spin* of salt, and muriatic acid; but was dis- 
covered in its gaseous state by Dr. Priestley, in 1772. 

Natural History. It issues from the craters of volcanoes, 
and is found in the warm springs of Mexico ; it exists in com- 
bination with ammonia, (the hydrochlorate of ammonia.) 

Process. 1. It can be obtained in the gaseous state, by 
simply heating the common hydrous hydrochloric acid of 
commerce in a glass flask, or retort, and collecting the gas 
over mercury. 

2. Put equal parts of common salt and sulphuric acid into 
a retort, and collect as above. 

Theory. Salt is a chloride of sodium, and sulphuric acid is com- 
posed of real acid and water ; the oxygen of the water goes to the 
sodium, and forms soda, which unites with the acid, and the hydrogen 
cf the water unites with the chlorine, forming hydrochloric acid. Na 
-f CI, SO 3 and HO, are converted into NaO-f-SO 3 and HC1. 

Instead of collecting the gas over mercury, it may be col- 
lected in large vials or bottles, in the following manner : — 

Put the materials into a flask, a, (see Fig. 64,) and connec. 
the flask with a glass tube, bent twice at right angles, and 
extending to the bottom of a bottle or receiver, b ; as the gas is 
heavier than the atmosphere, it will expel it, and fill the bottle. 
By the application of ammonia to the mouth of the bottle, a 
white cloud will arise when the bottle is filled.* 

Liquid Hydrochloric Acid. This is obtained in the arts 
oy passing the gas through water ; for this purpose Woulfe's 
apparatus may be employed. 

It consists of several bottles, b, c, d. e. (Fig. 79.) The first 
bottle is connected, by a lead tube, with a glass retort, a, which 
contains the materials ; b is one third filled with water ; the 
•tube from b descends to the bottom of c, and the gas passes 
up through the water. As soon as the water is saturated, 

* All gases that are heavier than the atmosphere, may be collected 
in this way, and those that are lighter maybe collected by inverting 
the bottle, and allowing the gas to press the air down, instead of lifting it up. 



Physical and Ciicmical Properties 



163 



Fisr. 79. 




>he gas passes through the tube to the bottom of d, and as- 
cends again through the water; thence to e, in a similar 
manner. Through the centre of each bottle there is a safety 
tube, extending nearly to the bottom, to prevent the danger 
that might arise from a too sudden evolution of gas. The 
gas presses upon the surface of the water, and forces it up 
the centre tubes, which prevents it from bursting the bottles. 
The acid in the first bottle is thrown away ; the rest is the 
acid of commerce. The bottles should be surrounded with 
ice, to aid the absorption . water will thus absorb 480 times 
its volume, and the solution has a density of 1.2109. 

Physical Properties. Hydrochloric acid gas is colorless, 
of a pungent odor, and acid taste, a little heavier than the 
air; sp. gr. 1.269; under a pressure of forty atmospheres, or 
GOO lbs. on the square inch, it is condensed into a liquid. 

Chemical Properties. It possesses decidedly acid proper- 
ties, chancres the vegetable infusions red, and combines with 
alkalies, and forms salts. It supports combustion feebly, and 
extinguishes a lighted taper, the flame of which assumes a 
greenish hue before it goes out. Water absorbs it rapidly. 

Exp. A drop or two of cold water, introduced into a flask of the 
acid, will absorb it readily; and if ajar of it be inverted over water, 
the water will rush in with nearly the same violence as into a vacuum. 

Exp. So strong is its affinity for water, that a piece of ice introduced 
into a jnr of it over mercury, will be dissolved almost as soon as if 
thrown into a furnace. 

It is readily decomposed by voltaic electricity, the hydrogen 
appearing at the negative and the chlorine at the positive 
pole. A discharge of ordinary electricity will decompose it, 
but, according to Henry, the second shock causes it to com- 
bine again. It is decomposed by those substances which 



164 Hydrochloric Acid. 

yield oxygen readily, such as the peroxide of manganese, 
cobalt, and lead ; the oxygen combines with the hydrogen of 
the acid, and sets the chlorine at liberty. 

It is nearly as suffocating, when taken into the lungs, as 
chlorine, causes spasms of the glottis, and combines with the 
saliva, or water, and forms the liquid acid. 

Constitution. It was formerly supposed to be a simple 
body, combining with oxygen to form oxymuriatic acid, now 
found to be chlorine. But its composition may be determined 
synthetically, by mixing equal portions of hydrogen and chlo- 
rine in a glass tube, and exposing them to the solar rays, 
when they instantly combine, with explosion, and hydrochlo- 
ric acid is the only product ; or their union may be effected 
by passing an electric spark through the mixture contained 
in the eudiometer.* If the gases are mixed, they will com- 
bine slowly in diffuse daylight. The light from the point, of 
charcoal, at the poles of a galvanic battery, has the same 
effect as the sun's rays. 

Uses. Hydrochloric acid is one of the three great acids 

used in the arts ; it is used for preparing the chloride of tin 

for dyers, as a re-agent in various chemical processes, and 

in medicine as a tonic. 

Impurities. The acid of commerce' is not quite pure, containing 
the chloride of iron, and chlorine. This gives the liquid a yellow 
color; but, when perfectly pure, it is limpid. 

Hydriodic Acid. Symb. H + 1. Eq. 126.3 + 1 = 127.3. 
Sp. gr. 4.3854, air=l. Discovered by Gay Lussac, of Paris. 

Preparation. It may be obtained by passing iodine vapor 
and hydrogen gas through a red-hot porcelain tube. But a 
more convenient process, by which it may be obtained for 
the purposes of experiment, is to put a small bit of phosphorus 
into a glass tube, filled with water, and drop upon it a fe>v 
grains of iodine. 

Theory. The iodine unites with the phosphorus, forming 
the periodide of phosphorus, and then the water and the 
periodide mutually decompose each other. The oxygen of 

* The fact being established that hydrochloric acid is composed 
of hydrogen and chlorine, the old theory that oxygen was the only 
acidifying principle is proved false ; there are many acids of hydrogen 
which have no oxygen in them. They are called hydracids. 



Hydrofluoric Acid. 165 

the water unites with the phosphorus, and the hydrogen with 
the iodine, giving rise to phosphoric and hydriodic acids ; the 
latter passes over in the form of a colorless gas, and may be 
collected in a receiver of common air; it may be passed 
through water, and absorbed by it. It cannot be collected 
over mercury, because it acts upon it. 

Properties. Hydriodic acid is a colorless, transparent gas, 
very sour to the taste, and gives an odor like hydrochloric 
acid ; reddens vegetable blues without destroying them, and, 
when mixed with air, produces dense white fumes; has a 
strong affinity for water ; is decomposed by several of the 
metals, such as potassium, sodium, zinc, iron, and mercury, 
and even when exposed to the air. 

Uses. This acid may be employed to form pigments. 

Exp. Take some of the salts of lead (acetate or nitrate of lead) in 
solution, and pour on hydriodic acid; it will decompose the salt, and 
form paints of a yellow color. 

Tests. The most delicate test of this acid is bichloride of 
platinum, a single drop of which, in solution, will give to a 
liquid containing the acid, a reddish-brown color, and a dark 
precipitate will subside. 

Exp. Starch is also a sure test. A few drops of sulphuric acid will 
give to a solution of the acid, mixed with a cold solution of starch, a 
blue color. 

Hydrobromic Acid. Symb. Br -|- H or BrH. Eq. 78.4 -f- ] 
= 79.4. Sp. gr. 2.7353. Discovered by M. Balard, and may 
be obtained by immersing a red-hot iron into a mixture of 
the vapor of bromine and hydrogen ; the combination takes 
place slowly, without explosion; or it may be formed, for ex- 
perimental purposes, by a process similar to that for obtaining 
hydriodic acid, using bromine instead of iodine. 

Properties. It is colorless, with an acid taste and pungent odor; 
irritates the glottis, so as to excite coughing ; exposed to moist air, it 
yields white dense vapors, and is rapidly absorbed by water ; decom- 
posed by chlorine instantly ; nitric acid also effects its decomposition. 

Hydrofluoric Acid, Symb. F + H or FH. Eq. 18.68 + 1 
= 19 38. Sp. gr. 1.0609. 

History. First procured in a pure state in 1810, by Gay 
Lussac and Thenar d. 

Process. It is formed by the action of sulphuric acid on 
fluor-spar, (fluoride of calcium ) This mineral is pulverized, 



166 Nitrogen. 

put into a lead or silver retort, with twice its weight of sul 
phuric acid, and heat applied. The acid will distil over, and 
must be collected in a vessel of the same material, surrounded 
with ice, to condense the acid. 

Theory. The hydrogen of the water in the sulphuric acid combines 
with the fluorine in the mineral, and the oxygen with the calcium; 
the sulphuric acid unites with the oxide of calcium : the products are 
hydrofluoric acid, and sulphate of the protoxide of calcium. Ca, F, SO 3 
and HO, are converted into CaO -f- SO 3 and FH. 

Properties. At 32° F. it is a colorless liquid, and remains 
in that state at 59°, if preserved in well-stopped bottles ; but, 
exposed to the air, it assumes the gaseous form, unites with 
the water of the atmosphere, producing white fumes. Its 
affinity for water is greater than strong sulphuric acid. Its 
vapor is much more pungent than chlorine or any of the irri- 
tating gases ; the most destructive to animal matter of any 
known substance, a single drop of the concentrated acid 
causing deep and almost incurable ulcers. It is distinguished 
for the remarkable property of acting on glass. It readily dis- 
solves silex, and an acid is produced called the fiuo-silicic 
acid ; and hence it cannot be preserved in glass vessels. 

Uses. It is used for etching on glass. 

Exp. For this purpose, prepare some resin or beeswax, and form a 
coat over the glass ; then, with a pointed instrument, remove the 
coating where you wish the glass to be etched ; pour on the acid, 
and in a few minutes the etching is completed. Then, by wash- 
ing the glass in water, and removing the coating, the figures will 
appear. The liquor in the retort will answer for this experiment, es- 
pecially if used within a day or two after the acid and the fluor-spar 

aremi * ed : ^-~}/« 

Sect, 7. Nitrogen. 

«„™k at iPrniJ* SM vol.100. „ , r C 0.9727 Air =1. 

Symb. N. Equiv. J J wgt um Sp. gr. J u 15 Hyd = L 

History. Nitrogen was discovered by Dr. Rutherford, of 
Edinburgh, in 1772. Three years after, Lavoisier discovered 
that it was a constituent of the atmosphere. Scheele also 
made the same discovery. It was called by Lavoisier azote 
(from two Greek words,*) because it deprived animals of life ; 
but this is not the only gas which is azotic. Its present 
name, nitrogen, is derived from nitre, (nitrate of potassa.) 

* A and tw^. 




Physical and Cliemical Properties. 167 

Natural History. Nitrogen exists in all animals, in fun « 
gous plants, and constitutes f of the atmosphere; also in 
some hot springs in Scotland, and in the Alps. It is also 
evolved from certain springs in the state of New York. 

Process. It may be obtained from the atmosphere, either 
by burning out the oxygen of a confined portion of air with 
some combustible, or by abstracting the oxygen in a more 
gradual way, by its affinity for some of the simple substances. 

Exp. 1. Put a small piece of phosphorus in a cup 
which will float on water, (Fig. SO.) and invert over Fig-. 80. 

it a receiver of common air. On igniting the phos- 
phorus,, it will unite with the oxygen, and burn until 
all the oxygen is consumed, forming white fumes — 
the pyrophosphoric acid. This- acid, in a short time, 
will be absorbed by the water, which will rise and fill 
the jar 4- full. This is sufficiently pure for common 
experiments, but contains vapor of phosphorus and 
carbonic acid, which may be removed by passing the 
gas through pure potassa. 

Exp. 2. Make a paste of flowers of sulphur and iron filings, and invert 
over it a receiver; the oxygen will combine slowly with the iron, and 
leave the nitrogen. A stick of phosphorus will produce the same ef- 
fect. If the proto-sulphate of iron, charged with the binoxide of nitro- 
gen, be substituted for the paste, the process is more rapid. 

Exp. 3. It may also be obtained by pouring nitric acid on fresh 
muscle, and subjecting it to a moderate heat. 

Theory. On account of the strong affinity of oxygen for 
these substances, it leaves the nitrogen, and combines with 
them. 

Physical Properties. Nitrogen is colorless, tasteless, 
inodorous, not condensed into a solid by pressure or cold. 
100 cubic inches weigh 30.1650 grains. 

Chemical Properties. Water, recently boiled, absorbs 1 J 
volumes of the gas. 

Nitrogen icill not support combustion. 

Exp. Put a lighted candle into a jar of it, and it will be immediately 
extinguished ; hence it does not support 

Respiration. No animal can live in it, not because of the 
active properties of the gas, but because it excludes the oxy- 
gen. It kills by its negative properties, for which it seems 
alone to be distinguished. The effect is like that of 
drowning. 

Nature of Nitrogen. Nitrogen has been supposed by 



168 Nitrogen and Oxygen. 

some, among, whom is Berzelius, to be a body composed Oi 
oxygen and an unknown base. But this base has never been 
exhibited in a separate state ; and, until that is done, it must 
be regarded as a simple substance. 

Although pure nitrogen is the most inert of substances, 
some of its compounds are among the most active and useful 

Nitrogen and Oxygen. 

Common Air. Symb. 2N + 0. Equiv. 28.30 + 8 = 
36.30, eq. vol. 4N + O. Sp. gr. = 1 The earth is sur* 
rounded by a gaseous fluid or atmosphere, consisting chiefly 
of common air, extending about forty-five miles from its sur- 
face, and revolving with it around the sun. 

Physical Properties. The atmosphere is a permanent, 
elastic fluid, transparent, inodorous, and tasteless. 

The air is very compressible and elastic 

Exp. The compressibility of the air may be shown by the fire-syringe, 
by which it may be compressed into a very small compass. If 100 
measures of confined air, under pressure of 1 lb., be subjected to double 
the pressure, or 2 lbs., it will be diminished to 50 measures; double 
this pressure, or 4 lbs., will compress it to 25 measures. On the other 
hand, if the pressure be diminished, its elasticity will restore it to its 
former state. Then, if £ lb. be applied to the 100 measures, it will ex- 
pand to 200 measures. Halve this, or \ of a pound, and the volume 
will be double, or 400 measures. The same is true of all other gaseous 
bodies, while they retain their gaseous state. Hence the following 
law, that 

The volume of air and of other gaseous fluids is inversely 
as the pressure applied. 

Exp. The elasticity of the air may be further shown by putting a 
bladder, half filled with air, under the receiver of an air-pump, and 
exhausting the air from the receiver; the external pressure being thus 
taken off, the air within the bladder will expand, fill the bladder, and 
even burst it. This force is often so great, as to burst the strongest 
vessels. Hence the danger of forcing too much air into the ball of an 
air-gun, or carbonic acid into a soda fountain. 

Winds. In consequence of the great elasticity and compressibility 
of the air, it gives rise to the phenomena of winds. It is subject to the 
laws of elastic fluids in general ; as one portion therefore becomes ex 
panded by heat, the colder or more dense portions rush rapidly inti 
its place, and force it to ascend. From the same properties, also, vi 
brations are easily produced in it, which give rise to the sensation of 
sound, musical tones, etc. 

Pressure of the Air. That the air had weight, was firs 
noticed by Galileo, in 1640. Torricelli, his pupil, carried ou'^ 



Common Air. 169 

his suggestions, and in 1643 invented the barometer* by 
which variations of pressure could be accurately measured. 
The exact weight of the atmosphere is of great importance 
in physical and chemical researches, and has been accurately 
determined by Dr. Prout. At the level of the sea, its pressure 
is 15 lbs. on every square inch of surface. 

Exp. This pressure may be illustrated by exhausting the air from 
the receiver of an air-pump; the pressure on the external surface of 
the receiver will fix it immovably to the plate. 

The body of a man sustains constantly a pressure of about 
14 tons ! 

As we ascend above the level of the sea, the mercury sinks 
m the barometer, because the column of air is shorter ; hence 
the height of mountains may be measured in a very expeditious 
manner. Aeronauts in this manner determine the height to 
which they ascend. f 

. Extent of the Atmosphere. The height of the atmosphere, 
as estimated by the phenomena of refraction, is found to be 
about forty-five miles. Above that height, no refraction takes 
place in the rays of light. Dr. Wollaston estimates its ex- 
tent, by the law of the expansion of gases, at forty miles; 
that is, the weight of the particles of air (gravity) will over- 
come their elasticity at^that height. 

• Composition of the Atmosphere. Chemists are not agreed 
whether the atmosphere is a chemical or a mechanical com- 
pound. The proportions 20 or 21 parts of oxygen and 79 or 
80 of nitrogen in 100 never vary, from whatever parts of the 
earth, or regions of the atmosphere, it may be taken. Gay 
Lussac brought air from an altitude of 21,735 feet, and its 
composition did not vary from that on the surface of the earth. 

Exp. That the atmosphere is composed of 4 parts of nitrogen and 
i of oxygen, by measure, may be shown by a graduated glass tube of 

* Torricelli first filled a glass tube three feet in length with mercury, 
and, on inverting it in a vessel of the same liquid, found that the mer- 
cury fell about six inches ; hence the atmosphere sustained a column 
of mercury of about thirty inches. The space abandoned by the 
mercury is called the Torricellian vacuum, and is the most perfect 
that can be formed. 

t There seems to be a constant relation between the pressure of the 
atmosphere and the weather. During a storm, the mercury in the 
barometex sinks, indicating that the atmosphere is lighter, and rises 
again when fair weather returns, proving its greater weight. Invalids 
often complain of the oppressive weight of air in foul weather ; the 
fact, as we have seen, is the reverse ; they feel a difficulty in respira- 
tion, because the air is too light. The same difficulty is felt by aero- 
nauts, and those who ascend high mountains. 
8 



170 



Nitrogen and Oxygen. 



Fig. 81. 




Known capacity, and bent as in Fig. 8t. Put a bit of 
phosphorus into the bent end, and place the open 
end in a vessel of water, keeping the finger over the 
end to prevent the air from escaping. Bring now 
near the phosphorus a red-hot iron; the phospho- 
rus will be inflamed, and will burn out the oxygen 
of the air ; phosphoric acid will be formed, and 
absorbed by the water ; the latter will rise, and fill 
the tube l-5th full ; the remaining 4-5ths is nitro- 
gen. 

This uniformity in the composition of the 

atmosphere has been regarded as a decisive 

proof of its chemical constitution. But it has 

been shown by Dalton, that it is the results of 

a mechanical, rather than of a chemical law. 

This law may be illustrated in the following manner : — 

Exp. Take two strong glass tubes closed at one end, and fill the 
one with oxygen and the other with hydrogen gas. Close the tube con 
taining oxygen with a cork, through the centre of which is inserted a 
small glass tube. Having inverted the tube containing the oxygen 
place upon it that containing the hydrogen, so that one cork shall close 
both tubes; let them remain in an upright position. A^ the oxygen in 
the lower vessel is sixteen times as heavy as the hydrogen in the upper, 
we should expect that each would maintain its position ; but the fact 
is otherwise. They mutually intermingle, as is proved by their forming 
explosive mixtures in both tubes. 

Similar experiments have been made upon a great number 
of gases, an r \ it is uniformly found that, after a little time, they 
will distr'oute themselves equally through the space occupied 
by botV , whatever be their difference of density : hence it was 
inferred by Dalton that different gases are vacuums in respect 
to each other; that is, that one gas does not prevent the en- 
trance of another into the space which it occupies, any more 
than the vacuum of an air-pump, although it will flow 
more slowly in the former than in the latter case. All gases 
and vapors follow the same law ; hence there are as many at- 
mospheres around the earth as there are gases upon its 
surface, each occupying the same space which it would oc- 
cupy if it were entirely alone. 

This tendency to diffusion renders it difficult to confine 

gases in bladders, or even over water in the pneumatic cistern 

Exp. By placing hydrogen gas in a glass tube, one end of which ia 
stopped by plaster of Paris, over water, the hydrogen will force itself 
out through this plaster so rapidly as to prevent the entrance of the 
air, and the water will rise in the tube ; but, as the water rises, the at* 
mc vpheric pressure is such as to force the air into the tube, and the 
wa ?r will fall. By igniting the gas, it will explode ; which shows thai 
tneie has been a mingling of the air with the hydrogen. 



Protoxide of Nitrogen. 171 

Impurities. The air usually contains other gases; car- 
bonic acid and watery vapor are the most abundant. The 
quantity of water is determined by the hygrometer. It never 
amounts to more than one per cent. Carbonic acid rarely 
exceeds TT5 Vo- Traces of hydrochloric acid are frequently 
found in the vicinity of the ocean, and of nitric acid in rain 
water, produced by lightning. 

The air near cities often contains other substances, organic 
matter, sulphuric acid, and ammonia. The odoriferous par 
tides of flowers, and other vegetable and mineral substances, 
are often detected in it. 

It was formerly supposed, that the healthy state of the air 
depended upon the proportion of oxygen in it ; hence the 
origin of the term cudiomctry , which was applied to the 
process of analyzing the air : but, since the oxygen of the 
air is found to be constant, it is now applied also to the 
modes of ascertaining its purity. This is effected either 
by exploding a given portion of air with hydrogen in the 
eudiometer, (see page 152,) or by placing in a portion of 
confined air some substance to abstract the oxygen. 

Uses of the Air. The utility of the atmosphere in the economy of 
nature cannot be too highly rated. It is absolutely essential to animal 
and vegetable life. Its constitution is one of the most beautiful illus- 
trations of the wisdom and goodness of the Creator. 

Protoxide of Nitrogen. Symb. NO. Equiv. 14.15 -j- 8 = 
22.15. Sp. gr. 1.5239. 100 cubic inches weigh 47.2586 grains 

History. Discovered by Priestley, 1772, and named by 
him dephlogisticated nitrous air. Davy called it nitrous oxide. 

Process. This gas may be formed by decomposing nitrate 
of ammonia. 

Ezp. Put a few grains of this salt into a glass retort, and apply 
heat. At a temperature of between 400° and 500° Fahr. it liquefies, 
bubbles of gas begin to appear, and in a short time brisk effervescence. 
The gas may then be collected in the ordinary way over warm water, 
and suffered to remain a short time, until the water absorbs the nitrous 
acic which is often formed with it. 

Tlieory. The changes which take place may be thus ex- 
plained : the NH 3 + NO 5 , containing 2N, 50, and 3H, are 
converted into 3HO, or water, and 2NO. 

Properties. The protoxide of nitrogen is a colorless, in- 
odorous gas, of a sweetish taste, and does not affect the vege- 
table blues ; it is not, therefore, an acid or an alkali. 



172 JSitrogcn and Oxygen. 

It supports combustion almost as powerfully as oxygen ga% 

Exp. A candle is relighted in the same manner as in oxygen gas 
Iron wire, charcoal, and most combustibles, burn in it. Phosphorus 
burns with nearly the same brilliancy as in oxygen gas. 

Exp. Mix equal volumes of the protoxide and hydrogen gas, and it will 
form an explosive mixture, which may be exploded in the gas pistol 
by flame, or the electric spark ; but generally it requires the temperature 
of the substance to be raised to a higher degree than oxygen, because 
the heat is necessary to decompose the gas, so that its oxygen may 
unite with the combustible, and its nitrogen escape into the air. 

Respiration of this Gas. When respired, it is a powerful 
stimulant. Its effects upon the animal system were first in- 
vestigated by Sir H. Davy in 1799. In his experiments on 
the effects of respiring the various gases, he breathed nine 
quarts of this gas for three minutes, and twelve quarts for 
four. No quantity would support respiration for a longer 
period. The effects are pleasurable -in the highest degree, 
resembling the first stages of intoxication. The effect varies 
very much with temperament, but generally gives an unusual 
propensity to muscular action, a rapid flow of vivid ideas, 
and the more prominent traits of character are made still 
more prominent. 

This excitement continues but for a few minutes, and gen- 
erally is not succeeded by the languor and exhaustion conse- 
quent upon other stimulants.* Its effects, however, upon some 
temperaments, have proved decidedly injurious. It is hoped 
that so powerful a stimulant will be applied to some good use 
in medicine. 

Binoxide of Nitrogen. Symb. N + 20, NO 2 or N. Eq. 
14.15 + 16 = 30.15. Sp. gr. 1.0375. 

History. Discovered by Dr. Hales ; but its properties were 
first investigated by Dr. Priestley, in 1772, who gave it the 
name of nitrous air. Nitric oxide and nitrous gas have also 
been applied to it. 

Process. It may be formed by the action of dilute nitric 
acid (2 parts of water to 1 of acid) upon copper filings, oi 

* It may be administered from a silk or India-rubber bag, furnished 
with a stop-cock, by repeatedly breathing it from the bag and back 
again, as long as it will support easy respiration. 



Nitrous Acid. 173 

mercury. Place the materials in a retort, and collect over 
water. 

Theory. In this process, the nitric acid is decomposed. 3 equiv. of 
oxygen unite with the copper, forming the peroxide of copper, and 2 
equiv. of oxygen combine with the nitrogen, and form the binoxide ; the 
peroxide of copper is then united to some undecomposed nitric acid, 
and forms the nitrate of copper. Cu and 2NO a are converted into 
Cu0 3 -f NO 5 and NO' 2 . 

Properties. This gas is colorless, and slightly absorbed 
by water. It is perfectly irrespirable, exciting spasms in the 
glottis, which immediately closes to prevent its passage into 
the lungs. It extinguishes most burning bodies, although 
phosphorus and charcoal, introduced in a state of vivid com- 
bustion, burn with increased brilliancy, owing, doubtless, to 
its decomposition, which is easily effected by heat or elec- 
tricity. 

Binoxide of nitrogen has a strong affinity for oxygen. 

Exp. Pass oxygen into a jar of it, and red fumes will be formed. 
This is a test of the gas. Atmospheric air will produce a similar ef- 
fect;* hence it may be used to separate the oxygen from the nitrogen 
of the air. 

Hyponitrous Acid. Symb. N + 30, NO 3 or N. Equiv. 
14.15 + 24 = 38.15. This compound was discovered by 
Gay Lussac, and is said to be formed when 400 measures of 
binoxide of nitrogen are mixed with 100 of oxygen, both 
quite dry. When the resulting orange fumes are exposed to 
a cold of zero, Fahr., they are condensed into a liquid. 

Properties. The anhydrous acid is colorless at zero, and 
green at common temperatures. It is so volatile, that, in open 
vessels, the green fluid wholly and rapidly passes off in the 
form of an orange-colored vapor, density of 1.72. In the 
manufacture of sulphuric acid, it exerts an important agency, 
by forming with water and sulphuric acid a crystalline com- 
pound, the production of which seems essential to the 
process. 

Nitrous Acid. Symb. N -f- 40, NO 4 or N. Eq. 14.15 + 
32 = 46.15. 

History. Known for some time under the name of fuming 
nitrous acid. Its true nature has been ascertained by Davy, 
Gay Lussac, and Dulong. 

* Owing to this property, an attempt has been made to introduce it 
mto eudiometry ; but the results are not perfectly satisfactory. 



174 Nitrogen and Oxygen. 

Processes. 1. It is formed by adding oxygen gas in excess 
to the binoxide of nitrogen over mercury, and putting a strong 
solution of potassa into the receiver before mixing the gases , 
red fumes appear, and combine with the potassa. 

2. It may be obtained in the form of a gas, by exhausting 
a glass globe of air, and introducing 100 volumes of oxygen 
to 200 volumes of the binoxide of nitrogen.* 

3. The best mode is to expose, in an earthen retort, nitrate 
of lead, carefully dried, to a red heat, and collect the gas in 
a tube surrounded by ice. For the purposes of experiment, 
it may be formed by introducing oxygen, or common air, into 
a jar of the binoxide, over water ; deep orange-red colored 
fumes appear, which are rapidly absorbed by the water ; or 
by simply taking up a jar of the binoxide, and exposing it to 
the air. In each case, nitrous acid is formed, and may be 
known by its red fumes. 

Properties. The vapor is of an orange-red color, rapidly 
absorbed by water. At common temperatures, the liquid is 
orange-red ; below 32°, yellow, and nearly colorless at zero, 
Fahr. ; density, 1.451 ; anhydrous, exceedingly volatile, pun- 
gent to the taste, and powerfully corrosive, giving a yellow 
stain to the skin. 

It has decided acid properties, f both in the gaseous and 

liquid states. 

Exp. Into a long glass tube, filled partly with vegetable infusion, 
and partly with the binoxide, introduce a few bubbles of oxygen ; the 
infusion will immediately turn red, owing to the formation of nitrous 
acid, and the absorption of it by the infusion. 

Respiration of Nitrous Acid. It is highly suffocating and 
poisonous, exciting great irritation and spasms in the glottis, 
even when moderately diluted with air. 

Nitric Acid. Symb. N + 50, NO 5 or N. Equiv. 14.15 
-|-40 = 54.15. 

History. This acid was first discovered in distilling s 
mixture of nitrate of potassa and clay, by Raymond Lully, 



* If collected over water, it is converted into nitric acid; if over 
mercury, it is decomposed, and the mercury is oxidized. 

t Some chemists believe it to be a compound of nitric and hyponi* 
trous acids, from the fact that, when it is added to an alkaline solution, 
the products are a nitrate and a hyponitrite of the base. 



Nitric Acid. 



175 



Fig. 82. 



a cneimst of the Island of Majorca. Basil Valer.tine, in the 
15th century, describes a process of obtaining it, and calls it 
the water of nitre. Its composition, however, was first de- 
termined by Mr. Cavendish, in 1785, by exposing oxygen and 
nitrogen in a glass tube over mercury, in which some water 
was present, to the action of the electric battery. It has 
since been examined by Davy, Dalton, Henry, Berzelius, and 
Gay Lussac. 

Process. Gay Lussac ob- 
tained nitric acid by adding the 
binoxide of nitrogen slowly to 
uri excess of oxygen over water. 
By this process, it is found to 
be composed of 250 volumes of 
oxygen to 100 of nitrogen. But 
the usual process for obtaining 
it, is to heat, in a large tubulated 
retort, a, (Fig. 82,) a mixture 
of 3 parts of nitre (nitrate of po- 
tassa) and 2 of sulphuric acid,* 
and condensing the gas in the 
globe receiver b, by dropping 

ice-cold water from the tunnel t upon the tube of the retort, 
or by surrounding the receiver b with ice. The liquid, as it 
is condensed, passes into the bottle C. 

Impurities. The acid of commerce is not perfectly pure; three 
acids are generated in the process — the nitrous, hyponitrous, and nitric. 
It also contains hydrochloric and sulphuric acids Nitrous acid gives 
it a color varying from yellow to orange and green, and may be ex- 
pelled by heat ; the hydrochloric may be detected and separated by a 
few drops of the nitrate of silver, with which it will combine and form 
a white solid. The sulphuric acid is separated by re-distilling it with 
nitre. m 

Properties. Nitric acid, in its most concentrated state, is 

a white or limpid liquid, specific gravity of 1.55, and of a 

peculiarly nauseous odor. It boils at 248°, and freezes at 

-50° Fahr. 




* The London College of Physicians employ equal weights of nitrate 
of potassa and sulphuric acid. The Edinburgh and Dublin Colleges 
employ 3 of nitre to 2 of acid. According to Thompson, the strongest 
acid is obtained from 6£ parts of sulphuric acid to 12| of nitre ; the 
Bpecific gravity of which is 1.55. 




176 Nitric Acid. 

CItemical Properties,, It is one of the most energetic of 
substances. It acts upon the skin, and gives it a yellovu 
stain ; it is eminently poisonous ; has a very strong affinity 
for water, and cannot be wholly separated from it, before 
decomposition takes place. 

It acts as a supporter of combustion ; in this case, it is 
decomposed, and the oxygen combines with the combustible. 

Exp. Pass hydrogen and nitric acid through an ig- Fig. 83. 
nited porcelain tube ; a violent detonation will be pro- 
duced, which is due to the combination of the oxygen of 
the acid and the hydrogen. 

Exp. Pour strong nitric acid on dry, powdered char- 
coal ; the charcoal will be ignited, with the evolution 
of dense fumes. 

Exp. Phosphorus takes fire in it, (Fig. 83,) sometimes 
with violent explosion. 

Exp. Pour nitric acid on to some of the essential oils, 
as spirits of turpentine, and they will be inflamed. 

The acid in these experiments should be pour- 
ed from a wine-glass, attached to the end of a 
long rod. 

Nitric acid unites with various metals, such as iron, tin, 
copper, with great energy, and is decomposed by them. It 
also suffers decomposition by boiling it in contact with 
sulphur, or by exposing it to the solar rays. In this case, 
the color changes to a yellow, and deep orange, in conse- 
quence of the formation of nitrous acid. The action of 
the binoxide of nitrogen produces the same effect, as may 
be shown by passing it through nitric acid. In consequence 
of its yielding up its oxygen so readily, it is one of the most 
powerful oxidizing agents. 

Uses. It is used extensively in chemistry and the arts; 
for etching on copper, and as a solvent of tin to form a mor 
dant for some of the finest dyes ; in metallurgy and assaying, 
to bring the metals to their maximum of oxidation ; in medi- 
cine, as a tonic. The nitric acid of commerce is J water, 
and called double aquafortis ; another kind, ^ water, is called 
simply aquafortis. 

NitrohydrocMoric Acid. This is the aqua regia of the 
alchemists, and is formed of 1 part of nitric to 4 of hydro- 



Nitrogen and Chlorine. 177 

chloric acid. It possesses the remarkable property of dissolv- 
ing gold and platinum, but does not form a distinct class 
of salts. 

Nitrohydrofluoric Acid. This acid is formed by a mixture 
of nitric and hydrofluoric acids, and dissolves metals, which 
are not dissolved by the preceding acid, and is therefore an 
important re-agent. 

Nitrogen and Chlorine. 

Quadrochloride of Nitrogen. Symb. N -f- 4C1 or NCI 4 . 
Eq. 14.15 + 141.6S =r 155.83. Sp. gr. 1.653. Discovered 

in 1811 by Dulong, and subsequently examined by Davy and 

others. 

Process. This very extraordinary substance may be formed by the 
union of nitrogen and chlorine in their nascent state, or the chlorine 
may be obtained in ajar, and inverted over a solution of 1 part of hy- 
drochlorate of ammonia to 12 of water; a part of the chlorine unites 
with the hydrogen of the ammonia, forming hydrochloric acid, and 
another portion unites with the nitrogen of the ammonia, and forms 
the quadro-chloride of nitrogen, which appears in the form of yellow, 
oily drops on the surface of the solution. 

Properties. A yellow, oily liquid, of an irritating and pe- 
culiar odor ; it retains the liquid state below zero, Fahr. It 
may be distilled at 160° Fahr., but explodes between 200° and 
21*2°, and suffers decomposition. It is one of the most explo- 
sive substances yet known. A drop of the size of a 'pea, 
brought in contact with phosphorus, or with any of the oils, 
will explode with great violence. It is dangerous to experi- 
ment with it, even in so small portions. Dulong lost an eye 
and a iinger ; and Davy had both eyes injured by exploding 
small quantities of it. As it is liable to explode without 
any assignable cause, great care should be used in its prepa- 
ration 

Nitrogen and Iodine. 

Tcriodide of Nitrogen. Symb. N + 31 or NF. Eq. 14.15 + 
378.9 = 392.24. This compound, discovered by M. Cour- 
tois, is obtained in a similar manner with the preceding. 

Exp. Put iodine in a solution of ammonia, and there will be precip- 
itated a blackish powder, which may be thrown, in the course of half 
an hour, upon a filter, washed and dried. When dry, it explodes by 
the slightest touch, or even spontaneously. 
8* 



ITS Nitrogen and Hydrogen. 



Nitrogen and Hydrogen. 

Ammonia. Symb. N + 3H or NH 3 . Eq. 14.15 + 3=; 
17.15. 

History. This substance was known to the alchemists by 
the names of hartshorn, volatile alkali, spirit of sal-ammo« 
mac, etc., but was first noticed as a distinct gas by Dr. Priest- 
ley, who gave it the name of alkaline air. The name ammo* 
nia is derived from one of the salts from which it was pro- 
cured, the hydrochlorate of ammonia, or sal-ammoniac, and 
this from the temple of Jupiter Amnion, in Lybia, from 
which place it was first obtained 

Process. Mix together equal parts of pulverized Fig. 84. 
hydrochlorate of ammonia and recently-slacked lime 
in a common retort, and apply heat. The gas may 
be collected over mercury, or, in consequence of its 
being lighter than the air, the materials may be put 
into a Florence flask, a, (Fig. 84,) to which is at- 
tached a long glass tube. Invert over it a receiver, 
r, and the gas will displace the air, and fill the re- 
ceiver ; (for a test of the gas, hydrochloric acid 
may be used, which produces a white cloud.) It 
may also be obtained by simply heating the com- 
mon aqua ammonia of commerce. The liquid ammonia, oi 
aqua ammonia, is prepared by passing the gas through water 
in Woulfe's apparatus, in the same manner as in the prepa- 
ration of hydrochloric acid. (Seepage 162.) 

Theory. When lime and the hydrochlorate of ammonia are used, 
the hydrochloric acid deserts the ammonia, and combines with the lime, 
leaving the former to escape in the gaseous form. 

Properties. Ammonia is a colorless gas, of a strong, pun- 
gent odor ; becomes a transparent liquid under pressure of 
6.5 atmospheres, and at a temperature of 50° Fahr. It cannot 
support respiration in its pure state, but may be inhaled with 
safety when mixed with the air. 

It is inflammable, but extinguishes the flame of most burn- 
ing bodies. 

Exp. A candle immersed in this gas, burns with incKeased flame, 
tinged with yellow before it goes out. When expelled from an orifice 



Nitrogen and Hydrogen. 179 

surrounded by oxygen gas, and ignited, it burns with a pale yellow 
flame. The products are water and nitrogen. 

It has a strong affinity for water and for alcohol. 

Exp. A few drops of water, introduced into a jar of the gas over 
mercury, will instantly absorb it, and the mercury will rise. 
Ice placed in ajar of it over mercury, is melted rapidly. 

Alcohol absorbs several volumes of this gas, and the solu- 
tion has a strong odor, commonly called spirits of hartshorn. 

The decomposition of ammonia is effected by chlorine and 

iodine. 

Exp. Place a flask of ammonia over a bottle with a wide mouth, 
containing chlorine gas. The gases will instantly combine, as will be 
seen by a sheet of white flame. 

Theory. The chlorine unites with the hydrogen of the ammonia, 
forming hydrochloric acid; and this unites with some undecomposed 
ammonia, and forms hydroehloraie of ammonia, and will be deposited 
on the sides of the flask in a solid state. 

Ammonia, both in the gaseous and liquid form, possesses 

decided alkaline properties* 

Exp. Place a jar of ammoniacal gas on a plate containing vegetable 
infusion, and the infusion will become green. 

Uses. Ammonia is used in the arts and in medicine. In 
chemistry, it is employed to neutralize acids. 

Exp. Colors changed by acids may often be restored by ammonia. 
Hence clothing spotted by acids, especially woollen clothes, may have 
the color restored by moistening the spots with the liquid ammonia. 

In medicine, it is used as a tonic. It is a powerful and 

* Ammenium (Eq. NET 4 ) is a hypothetical compound of nitrogen and 
hydrogen. Although it has never been isolated, yet many chemists have 
inferred its existence. When ammonia is decomposed by a voltaic cur- 
rent, the nitrogen escapes at the positive and the hydrogen at the negative 
pole ; but if the negative pole terminate in a cup of mercury, the hydro- 
gen unites, it is supposed, with the nitrogen in the proportion of NH 4 , 
forming a compound which unites with the mercury, causing it to swell 
up and assume the consistency of soft butter. But this spongy mass be- 
gins to suffer decomposition as soon as the current ceases, yielding ammo- 
nia and hydrogen, while the mercury regains its original state. 

Ammidogen (NH 2 ) is another hypothetical compound similar to the above, 
which has been supposed to be the base or radical of all the ammonia 
compounds. Thus, when ammoniacal gas (NH 3 ) is heated with potas- 
siu ii, thire is formed a compound having the composition NH 2 K, or con- 
taining one equivalent of hydrogen less, the H being evolved in the 
process. So ammonia may be considered as composed of NH 2 -j-H. See 
Organi; Chemistry. 



t 



180 Carbon. . 

grateful stimulant, producing the useful effects of alcohol, 
without its injurious consequences. Ammonia is the sub 
stance employed for smelling-bottles.* 

i- 

Sect. 8. Carbon. 

s 7mb .c. E ^^;« 3 s P . g ,^w r=L 

Natural History. Carbon is one of the most important 
and useful of substances. Like all other substances of ex* 
tensive utility, it is widely diffused. It exists abundantly in 
the animal, vegetable, and mineral kingdoms. The greater 
part of the substance of trees, and of animal bodies, is car- 
bon It is rarely found quite pure in nature, and cannot 
be formed perfectly pure by art. The only pure carbon is 
the diamond. 

TJie diamond is found in the East Indies and in Brazil, 
S. A. They generally occur in alluvial soils, in detached crys- 
tals, the primitive form of which is the regular octohedron, 
but„sometimes have twenty-four, and even forty-eight faces. 
They are of various colors, brown, black, red, blue, and green, 
or colorless and transparent ; the latter are the most valued.f 
The diamond is the hardest body in nature. It is a powerful 
refractor of light, a property which led Newton to predict its 
combustion. Lavoisier first proved it to contain carbon, by 
exposing it in oxygen gas to the solar focus. The product 
was carbonic acid. In 1807, the combustion of the diamond 
in oxygen was found by Allen and Pepys to be attended by 
the same results as that of charcoal. Davy confirmed these 
results by comparing the combustion of the diamond with 
that of various kinds of charcoal. Another proof of its iden- 
tity is the fact, that diamond converts iron into steel in the 
same manner as charcoal. 

* To prepare a smelling-bottle, it is only necessary to put a small 
Quantity of quick lime and hydrochlorate of ammonia into a small bot- 
Ue, and keep it corked tight, only when it is used. 

* Diamonds are of various sizes ; some are as large as a pigeon'f 
egg, and the value increases with the size in a very rapid ratio. 



Carbon. 181 

Uses. The diamond is the most valued of gems ; used in 
# ewelry, and for the purpose of cutting glass. 

The other kinds of carbon are the following : — 

Plumbago. This is carbon nearly pure, containing four 
or five per cent of iron. It is sometimes called black lead, 
and used for pencils, crayons, etc. It is found native in 
primitive formations, and is next to the diamond in purity. 

Anthracite is a species of fossil coal, the next in purity. 

Bituminous coal is similar to the preceding, with the addi- 
tion of bitumen, when the bituminous and volatile matter is 
driven off by heat ; it is called coke, which is nearly pure 
carbon. 

Peat is an impure kind of carbon, containing uncarbon- 
ized vegetable matter, mixed with earthy substances. 

Lampblack is a kind of carbon which is obtained by the 
combustion of turpentine, pitch-pine, camphor, and almost 
any species of combustible matter, containing carbon. It is 
deposited from flame in the form of a fine black powder. 
For use in the arts, it is chiefly made by turpentine manufac- 
turers, from the refuse resin. This is burned in a furnace, 
and the smoke, carrying up the carbon, is conducted to a 
room hung with sacking, upon which the lampblack is depos- 
ited. It is collected and sold without further preparation. 
It is used extensively as a paint — that from camphor is the 
best. 

Ivory black is a kind of lampblack obtained from burning 
bones, sometimes called animal charcoal. 

Charcoal. If wood be burned in the open air, nothing 
remains but ashes ; but if the air is mostly excluded, so that 
it undergoes a smothered combustion, a black, brittle sub- 
stance remains, called charcoal, which is nearly pure carbon 

Processes. 1. For the common purposes of fuel, it is pre- 
pared by forming the wood into a conical pile, and covering 
it with earth. The combustion is slow, in consequence of 
the small quantity of air which is admitted ; the volatile parts 
are driven off, and the carbon remains. 

2 It is also prepared by distillation of wood, in large iron 



182 



Carbon. 



cylinders. This is the mode of preparing it for the manufac* 
ture of gunpowder. Beside the charcoal, two valuable sub- 
stances, the pyroligneous acid and tar, are obtained. 

3. But the purest charcoal is prepared by charring wood 
under sand or melted lead. It should be put immediately 
into bottles, corked tight, to exclude the air. 

Properties. Carbon is a black, brittle, shining, inodorous 
substance, easily pulverized, a good conductor of electricity 
and a bad conductor of caloric. 

It is the hardest substance in nature. Common charcoal 
appears soft, but this is in consequence of its pores. If 
rubbed upon glass, it will scratch it. 

It has the property of absorbing various gaseous bodies. 

Exp. Heat a piece of charcoal, and plunge it into mercury until 
cool, then place it under a glass receiver over mercury. In the course 
of twenty-four or thirty-six hours,, it will absorb of ammonia 90 timea 
the volume of the charcoal: 



Hydrochloric acid, . 
Sulphurous acid, . . 
Hydrosulphuric acid, 
Protoxide of nitrogen, 
Carbonic acid, . . . 



defiant gas, 35 

Carbonic oxide, .... 9.42 

Oxygen, 9.25 

Nitrogen, 7.5 

Hydrogen, 1.75 



The gases will be given up again by heating the charcoal, 
or partially by plunging it into water. 

Theory. This power cannot be attributed wholly to chemical action, 
but is due to the porous texture of the charcoal ; and the gases appear 
to be absorbed in the same manner that sponges and other porous 
bodies absorb liquids. The property is most remarkable in the com- 
pact varieties, such as that from box-wood, where the pores are numer- 
ous and small. By reducing it to powder, this power is diminished. 
In plumbago, and in the diamond, it is wholly wanting. 

But how does this account for its absorbing more of one gas than of 
another ? Chsmical affinity has doubtless some influence, but it is 
mostly due to the elasticity of the gases. Those gases, easily converted 
into liquids, are absorbed in greater quantities than those more perma- 
nent; hence vapors are absorbed more easily than gases, and liquids 
than ether. Hence, too, charcoal, when exposed to the air, or other 
gases, increases in weight* 



* The increase varies with the kind of wood from which it is made. 
According to the experiment of Allen and Pepys, charcoal from fij 
gains 13 per cent. ; lignurnvitae, 9.6 per cent. : that from 

Box, .14. I Oak, 16.5 

Birch, 16.3 | Mahogany, . . 18. 



Properties. 183 

The absorption is the most rapid during the first twenty- 
'our hours ; it absorbs oxygen from the air more rapidly than 
aitrogen. 

Ii also absorbs the odoriferous and coloring principles 
from most animal and vegetable substances. 

Exp. Pass ink through pulverized charcoal, and the color will oe 
discharged. Red wines, rum, and brandy, may be rendered colorless 
Dy nitration through it. 

It is used extensively for refining sugar, and for preparing 
colorless crystals of citric acid, and other vegetable produc- 
tions Stagnant water, and most animal and vegetable sub- 
stances, in a putrescent state, will be cleansed and purified 
by this substance ; hence its use to purify docks, vessels, etc. 
Putrescent meat is purified by rubbing it with charcoal ; 
and, generally, all substances subject to putrescence may 
be preserved for a long time, by surrounding them with 
charcoal. 

In consequence of this property, it is used in medicine as 
an antiseptic in putrescent diseases. Animal charcoal is the 
best for these purposes, and as its efficacy depends upon its 
power of absorption, it should be heated, to expel all the gas., 
before it is used, or kept in well-stopped bottles as soon as 
prepared. 

It is very combustible. It requires a strong heat to ignite 
it, but then it will burn for a long time, the oxygen of the 
air uniting with it and forming carbonic acid.* In conse- 
quence of this property, it is one of the most useful substances 
in nature. 

It is the most durable substance known. Grains of wheat 
and rye charred in Herculaneum by the volcanic eruption, 
A. I>. 79, were easily distinguished from each other, eighteen 
centuries afterward ; an arrow head has been charred, and 
even the form of the feather preserved. The stakes driven 
down in the bed of the Thames, by the Britons, to prevent the 
army of Julius Caesar from passing the river, were discovered 
about fifty years since, and were all charred to a consider- 
able depth. They were as perfect as when driven ; were 
made into knife-handles, and sold as antiques at a high 
price. Farmers char their troughs and posts to prevent 
decay. 

* Large quantities of powdered charcoal often ignite spontaneously , 
owing, doubtless, to the small quantity of potassium which is gener- 
ally found in oonaectioa with it 



184 Carbon. 

It is infusible by any degree of heat, except that fro .11 a 
powerful galvanic battery ; and in this case there is reason to 
doubt whether there is a fusion of any thing but of some im- 
purities in the carbon. 

Uses. The uses of carbon have already been stated, and 
are generally well known. It is one of those substances 
which are indispensable to the wants, to the existence of our 
race ; and the Creator has given us, in its character and 
abundance, the most decisive proofs of his wisdom and 
benevolence. 

Carbon possesses extensive powers of combination, and 
forms a class of substances of great and permanent utility in 
chemistry, the arts, and the common business of life. 

Carbonic Oxide. Symb. CO or C. Equiv. 6.12 +8= 14.12. 
Sp. gr. 0.9727, air=l. ' 

History. Discovered by Priestley by the distillation of 
charcoal with the oxide of zinc ; but its composition was 
first determined by Mr. Cruickshank. 

Process. The best and most convenient mode of obtain 
ing this substance, is to put 2 parts of well-dried chalk, 
pulverized, to 1 of iron filings, into a gun-barrel, and raise 
the temperature to a red heat. The gas may then be col- 
lected over water ; it may be obtained, also, by heating the 
oxides of several of the metals with powdered charcoal. 

Theory. Chalk is composed of carbonic acid and lime. One equiv-* 
alent of oxygen contained in the acid, goes to the iron, and converts 
the acid to the carbonic oxide ; oxide of iron and lime remain, or CO ? 
-{- CaO and Fe are converted into FeO, CaO, and CO. 

Properties. A colorless, insipid gas, of an offensive odor. 

It is highly inflammable, and burns with a pale blue flame 

when a lighted taper is plunged into it, but does not support 

combustion. A mixture of 1 part of oxygen to 2 of the 

gas is explosive ; the result is carbonic acid. It is dcstruc 

live to animal life; an animal immersed in it soon dies 

When diluted with air, it causes fainting and giddiness. 

Carbonic Acid. Symb. C +20, CO^ or C. Equit. 6.12 
+. 16 = 22.12. Sp. gr. 1.5239, air=l. 

History. Discovered in 1757 by Dr. Black, who called 



Carbonic Acid. 185 

it fixed air* This was the first gas known, except the 
atmosphere, and laid the foundation of pneumatic chemistry. 
Natural History. Carbonic acid exists very abundantly 
in nature, generally in combination with lime, forming the 
carbonate of lime, or marble. 

Process. It is obtained by the combustion of the diamond 
in oxygen gas, -or by burning charcoal in the air, or oxygen ; 
but it is more easily obtained by decomposing some of the 
carbonates. Take pulverized carbonate of lime (marble or 
chalk) in a glass retort, and pour on sulphuric or hydro- 
chloric acid, diluted with five or six parts of water, and 
collect over water, or in a globe receiver, in the same man- 
ner as hypochlorous acid gas.f (See page 138.)' 

Theory. In this process, the sulphuric acid combines with the lime, 
forming the sulphate of lime, and liberates the carbonic acid. SO 3 , 
CO' 2 -f-CaO are converted into S0 3 -f-CaO and CO 3 . 

Properties. It is colorless, inodorous, and elastic, requir- 
ing a pressure of thirty-six atmospheres, 540 lbs., to the 
square inch, to condense it into a liquid — more than 1J times 
as heavy as atmospheric air, and hence may be poured from 
one vessel to another, like water. 

It is neither a combustible nor a supporter of combustion. 

Exp. Into a jar of carbonic acid, let down a pendent candle. It will 
be extinguished as soon as it reaches the gas, or it may be poured upon 
the candle from a vessel. The flame does not cease from want of oxy- 
gen, since four measures of air and one of carbonic acid will extin- 
guish flame ; hence a positive influence i3 exerted upon it. 

It is rapidly absorbed by water. 

Exp. If a small quantity of water be agitated in a bottle containing 
carbonic acid gas, it will soon absorb it, and acquire acid properties. 

Recently-boiled water will absorb one volume of the gas at the com- 
mon temperature and pressure, but increases in its absorbing power in 
proportion to the pressure applied. It absorbs twice its volume when 
the pressure is doubled, three times its volume when the pressure ig 
trebled, etc. 



* Its composition was first demonstrated synthetically by Lavoisier, 
who obtained it by the combustion of charcoal in oxygen gas. Smith- 
eon Tennant proved its composition analytically by passing the vapoi 
of phosphorus over chalk, heated to redness in a glass tube. 

t If intended to be kept long, it should be transferred from the cis- 
tern in bottles, as the water rapidly absorbs it. 



186 



Carbon. 



Water may be acidulated with it, by employing Woulfeh 
apparatus, in the same manner as with hydrochloric acid. 
(See page 162.) In the common soda fountains, the water 
is confined in a strong brass or copper vessel, and charged 
with the gas by a forcing-pump. The pleasant, pungent 
taste and sparkling appearance of fermented liquors, soda, 
and Seidlitz waters, and the waters of many mineral springs, 
are due to the carbonic acid which they hold in solution. 
The water saturated with it makes a pleasant and healthful 
drink. 

But the gas escapes on exposure to air and heat. Hence 
all such drinks soon become insipid. 

If the pressure is removed, the escape 
of gas is much more rapid. 

Exp. Place a tumbler of water, (Fig. 85,) satu- 
rated with this gas, under the receiver a of an 
air-pump b, and exhaust the air. The gas will 
escape so rapidly as to present the appearance 
of boiling. Any of the fermented liquors will 
produce similar phenomena. 

If the water saturated with the acid 
be rapidly congealed, the frozen water 
has the appearance of snow, its bulk 
being greatly increased by the immense 
number of bubbles formed by the liber- ^ 
ated gas. 

It is an acid, as shown by chemical tests. 

Exp. Put a piece of litmus paper into water saturated with it, and 
it is turned red ; but by heat, or exposure to the air, the color returns, 
owing to the escape of the acid. 

This is not the case with any other acid ; the colors they 
form are generally permanent, unless changed by alkalies. 

The best test of carbonic acid is lime water, which is ren 
dered turbid by the gas. 

Theory. Carbonic acid unites with the lime which the water holds 
m solution, and forms the carbonate of lime, which is soluble in water, 
and is precipitated in fine powder. This gives to the water a milky 
appearance. If, however, you continue to add carbonic acid, it will 
dissolve the carbonate, and the water will become clear again, carbon' 
ate of lime being very soluble in excess of carbonic acid. 

Solidification of Carbonic Acid. It has lately been ascer 




Carbonic Acid. 187 

tained, that when the gaseous carbonic acid is subjected to a 
pressure of thirty-six atmospheres, it is condensed into a 
liquid, and at -85° into a solid resembling compact snow.* 

Relations to Animal Life. Although water saturated with 
carbonic acid proves a healthful and invigorating drink, the 
free acid cannot be taken into the lungs without producing 
almost instant death ; in fact, the glottis closes at its ap- 
proach, and will not suffer it to enter. If it be diluted with 
air, it acts upon the system as a narcotic poison ; an animal 
thrown into it is usually suffocated. f Carbonic acid is 
heavier than the air, and hence often remains in wells and 
deep pits, where it is generated, and called by the miners 
choke-damp. Before descending, a candle should be let 
down, and if it will not burn, life cannot be supported. The 
acid may be absorbed by pouring down large quantities of 
water ; it may be partially expelled by exploding gunpow- 
dej near the bottom ; or it may be drawn up with large 
buckets. 

Production of Carbonic Acid. Causes are in constant 
operation to form carbonic acid, and throw it off into the 



* Mr. Faraday first condensed carbonic acid into a liquid by placing 
carbonate of ammonia in one end of a strong glass tube, bent twice at 
right angles, and sulphuric acid in the other end, which is sealed her- 
metically. When the acid is poured upon the ammonia, it com! ines 
with it and liberates the gas, which, by the pressure, is condensed ; 
but this process is attended with much danger, from the bursting of 
the tube. A safer method has been contrived by Thillorier, in which 
the gas is condensed in a strong metallic cylinder. By allowing the 
liquid acid to escape through the stop-cock, it expands so rapidly as to 
become frozen, owing to the absorption of its sensible caloric. A re- 
duction of temperature to -162° is said to have been produced by this 
means. The solid acid thus formed is about the weight of carbonate 
of magnesia, perfectly white, and of a soft, spongy texture. It evapo- 
rates so rapidly that mercury, and even alcohol, (sp. gr. .820,) are frozen. 
According to the experiments of Mitchell, of Philadelphia, the greatest 
cold produced by the solid acid in the air was -109°, and under an 
exhausted receiver -130°. The pressure at 32° was 36 atmospheres, 
at GG°. CO atmospheres, and at 86°, 72 atmospheres, or 1290 lbs. to the 
square inch. When obtained in a liquid form in a glass" tube, it is 
colorless and extremely fluid In attempting to open the tubes at one 
end T they uniformly burst into fragments, with violent explosions. 

t CaiUwn. This gas is always produced in burning charcoal ; and 
hence the danger and criminality of placing pans of hot coals in 
Bleeping apartments, or in rooms not ventilated by a chimney. The 
acid gradually mixes with the air, causing drowsiness, and even death, 
before the person can escape. Every year adds new proofs, in the loss 
of many lives, to the folly and danger of such practices. 



188 Carbon. 

atmosphere. It is evolved in great quantities from the earth, 
from ordinary combustion, and by the respiration of animals. 
In the two last cases, the oxygen of the air is consumed, and 
carbonic acid takes its place ; hence we should .expect, if 
there were nothing to counteract this process, that the whole 
atmosphere would, in time, be rendered unfit to support 
respiration ; but not more than T oW P art °f tne atmosphere 
is carbonic acid. In places near cities, or where it is evolved 
from the earth, the proportion may be greater. This ten- 
dency, however, may be counteracted by the vegetable king- 
dom. During the daytime, plants absorb carbonic acid, de- 
compose it, retain its carbon, and throw off its oxygen. In 
the night, the process is reversed; oxygen is consumed, and 
carbonic acid is thrown off; but more of oxygen is emitted 
in the daytime than is consumed in the night; more carbonic 
acid also is consumed during the day than is given off dur- 
ing the night. The balance from this process is needed to 
meet the demands of the animal kingdom, which constantly 
consumes oxygen, and generates carbonic acid in the process 
of respiration. Thus the equilibrium of the atmosphere is 
preserved, and both kingdoms flourish together, 

Exp. That carbonic acid is given off in respiration, may be shown 
by breathing with a quill through lime water, which will become tur- 
bid. This fact enables us to understand the process of 

Respiration. The blood, in its progress through the sys- 
tem, becomes filled with carbon, which gives to it a dark 
color. When it passes into the lungs, the air is brought in 
contact with it ; the carbon unites with the oxygen, forming 
carbonic acid, which is expelled, and the blood is .changed 
to a bright red ; it is now fitted to nourish the system. Some 
suppose that the oxygen enters into the blood, and that the 
combination takes place during the course of circulation ; but 
whichever theory be adopted, carbonic acid is thrown off 
and oxygen is consumed. Hence, in crowded assemblies, 
great quantities of this gas are formed, and, as a consequence, 
dulness and fainting often ensue. Hence, also, the neces- 
sity of having large public rooms well ventilated. 

DicMoride of Carbon (Symb. C 2 C1. Equiv. 12.24 -4- 35.42 = 47.66) 
w r as discovered by M. Julin. It occurs in small, soft, adhesive fibres, 
of a white color, of a peculiar odor, resembling spermaceti, and is taste' 
less; burns with a red flame, emitting much smoke, and fumes of hy- 
drochloric acid gas. 

Protochloride of Carbon. Symb. CC1. Equiv. 6.12 -f 35.42 = 41 .54. 
It is obtained by passing the vapor of perchloride of carbon through q 



Compounds of Carbon, 189 

heated glass tube, filled with fragments of rock crystal, to increase the 
heated surface. It is a limpid, colorless liquid; density, 1.5526. 

I Chloride of Carbon. Symb. C 4 C1 5 . Equi v. 24.48 -f 177.1 =201.58 
Discovered by Liebig, and sometimes called the ncio chloride of 
Liebig; obtained by boiling chloral with a solution of lime, potassa, or 
baryta. It is a limpid, colorless liquid, similar in odor and appearance 
to the oily fluid which chlorine forms with olefiant gas ; density, 1.4S ; 
boils at 141° Fahr 

Perchloride of Carbon. Symb. C 2 CR 12.24 -f 106.26 = 118.5. Dis- 
covered by Faraday. When olefiant gas is mixed with chlorine, com- 
bination takes place between them, and an oil-like liquid is formed, 
consisting of carbon, hydrogen, and chlorine. Expose this liquid, in a 
jar of chlorine, to the solar rays, and hydrochloric acid is set free, and 
the chloiine unites with the carbon. 

Properties. At common temperatures, it is a colorless, transparent 
solid, of an aromatic odor, resembling that of camphor ; fuses at 320°, 
and boils at 300°. 

Chloro-carbonic Acid. Symb. O -f- C -f Ci. Equiv. 8 -f- 6.12 + 35.42 
= 40. 54. This singular compound of oxygen, chlorine, and carbon, 
affords a somewhat unusual instance of two acidifying principles 
uniting with one base to form an acid. It was discovered by Dr. 
Davy, who called it Phosgene gas. It is formed by exposing equal 
volumes of chlorine and carbonic oxide to the solar rays, when rapid 
but,silent combustion takes place, and they contract to one half their 
volume. 

Properties. A colorless gas, with a strong odor ; reddens litmus pa 
per, and combines with four times its volume of ammoniacal gas. Wa 
ter and several of the metals decompose it. 

Chlorid (Symb. C 9 C1 G 4 . Equiv. 299.60) is a new compound of 
carbon, oxygen, and chlorine, discovered by Liebig, and prepared by 
the mutual action of alcohol and chlorine. It is a colorless, transparent 
liquid, of a penetrating, pungent odor, nearly tasteless, oily to the 
touch ; density, 1.502, and boils at 201°.- 

Per iodide of Carbon was discovered by Serullas, and is obtained by 
mixing an alcoholic solution of pure potassa and of iodine. It forms 
crystals of a pearly lustre, sweet to the taste, and of a strong, aromatic 
odor, resembling saffron. 

The Protiodide is formed by distilling a mixture of the preceding 
compound with corrosive sublimate. It is a liquid of a sweet ta^te, and 
penetrating, ethereal odor. 

Bromide of Carbon. Formed by mixing 1 part of periodide of 
carbon with 2 of bromine : two compounds are formed, the bromide 
oj carbon and the sub -bromide of iodine; the latter is removed by a 
solution of caustic potassa. It is liquid at common temperatures, but 
crystallizes at 32° Fahr. ; sweet to the taste, and of a penetrating, ethe- 
real odor ; distinguished from the protiodide by the vapor which it emits 
on exposure to heat 



190 Carbon and Hydrogen. 

Carbon and Hydrogen, 

Two compounds of carbon and hydrogen have been known 
for some time, but of late the number has been increased to 
at least twelve. 

Di carburet of Hydrogen. Symb. C -j- 2H or CI P. Equiv. 
0.12 + 2 = 8.12. Sp. gr. 0.5593, air == 1. 

History. This substance is generally known under the 
name of light carbureted hydrogen. The names heavy in- 
flammable air, the inflammable air of marshes, and hydro- 
carburet, have also been applied to it ; but, taking carbon as 
the electro-negative element, it is more agreeable with the 
principles of nomenclature to call it a dicarburet of hydrogen. 
Dalton first ascertained its real nature, but it was subse- 
quently examined by Davy, Thompson, and Henry. 

Process. This gas is formed naturally by the decomposi- 
tion of vegetable matter in marshes. It may be obtained by 
inverting a receiver in almost any stagnant pool, and stirrinor 
the sediment at the bottom. In this state it contains one 
twentieth part of carbonic acid, and one fifteenth of nitrogen ; 
the former may be removed by lime water or pure potassa. 
This is the best mode to obtain the pure gas. 

It is formed also by the distillation of mineral coal, con- 
taining carbonic acid and olefiant gas ; the former may be 
removed by lime water, the latterly chlorine. 

Properties. Colorless, tasteless, arid nearly inodorous. 
Water absorbs ^ of its volume. It extinguishes all burnino 
bodies, but is highly combustible. It burns in a jet with a 
yellow flame, brighter than hydrogen ; destructive to animal 
life when respired ; partially decomposed by a very intense 
heat. 

Exp. Mixed with rather more than twice its volume of oxygen, it is ex- 
plosive ; exactly two volumes of oxygen are consumed, and the prod. 
acts are carbonic acid and water. 

Exp. Mixed with moist chlorine gas, and exposed to the solar light, 
it is decomposed, and hydrochloric and carbonic acids are formed; 
though the products will depend upon the quantity of chlorine. 

Olefiant Gas, or -f Carburet of Hydrogen. Symb. 2C + 
2H. Eqviv. 12.24 + 2 = 14.24. Sp. gv. 0.9808, = 1. 



Carbon and Hydrogen. 93 

History. Discovered in 1796 by some associated Dutch 
f hemists, who called it olefiant gas from its forming an oil- 
like liquid with chlorine. It has been called hyduret of car 
bon, bicarburcted or percarbureted hydrogen; but § carburet 
of hydrogen accurately designates its composition, and is, on 
this account, preferable. 

Process. Mix in a large retort 1 measure of alcohol with 
2 of concentrated sulphuric acid, and apply the heat of a 
-spirit lamp. The mixture soon turns black, and rises up in 
the retort ; the gas is rapidly disengaged, and may be col- 
lected over water or mercury ; carbonic and sulphuric acids 
are formed during the process, and may be separated by pure 
potassa or lime water. 

Theory. Alcohol is a compound of olefiant gas and water. The 
sulplmric acid unites with the water, and the gas is evolved. C 2 H 3 G 
and SO 3 are converted into SO 3 , HO, and C^H 2 . At the commence- 
ment of the process, ether is formed, which differs from alcohol by hav- 
ing 2 equiv. of olefiant gas combined with water, while alcohol has but 
1. The ether is condensed in the cistern. 

Properties. It is a colorless, tasteless gas, and has scarcely 
any odor when pure. Water absorbs £ of its volume. It 
extinguishes 'a lighted taper when immersed in it, and there- 
fore does not support respiration. It burns with a clear, white 
light. 

Mixed with oxygen, it is highly explosive. 

Exp. Mixed with oxygen in the proportions of 1 volume of the gas 
to 3 of oxygen, and kindled by flame, or the electric spark, it explodes 
with great violence. This may be shown by the gas pistol. There is, 
however, much danger of bursting the pistol; glass vessels should 
not be employed to explode it. 

Exp. Bubbles of the mixture may be passed up through the water 
of the cistern, and exploded upon the surface ; but care should be taken 
tha: the fire is not communicated to the vessel containing the mixture, 
through the bubbles as they rise. 

It is decomposed by heat. By passing it through a porce- 
lain tube at a low red heat, charcoal is deposited, and the 
bicarburet evolved, which, at a white heat, is also decom- 
posed. It is also resolved into hydrogen and carbon by a 
succession of electric shocks. 

Action of Clilorine. When 2 volumes of chlorine and 1 
of olefiant gas are mixed and ignited, they burn rapidly, 



A 92 Carbon. — Gas Lights. 

and form hydrochloric acid, while the carbon is deposited 
but, if the-gases remain at rest, they slowly combine, and form 
an oily liquid, of a yellow color, called chloride of hydro- 
carbon. 

f- Carburet of Hydrogen, Etherine, (Symb. 4C + 4H. Equiv. 24.48 
4-4 = 28.48. Sp. gr. 0.627, water = 1,) was first obtained by 
Faraday in the process of compressing oil gas into strong copper 
globes, for the supply of portable gas. It is a highly volatile liquid, 
the lightest liquid body known. At 60°, it is exceedingly combustible, 
and burns with a brilliant flame. 

f Carburet of Hydrogen (Symb. 6C -f 3H. Equiv. 36.72 + 3 = 
39.72. Sp. gr. 0.85) was obtained by Faraday from the same oil gas 
liquid which yielded etherine. At common temperatures, it is a color- 
less, transparent liquid, smells like oil gas, with a slight odor of almonds. 
It is highly combustible, and forms with oxygen a powerful detonating 
mixture. 

ParraJJine is a compound of carbon and hydrogen, obtained by the 
distillation of the petroleum of Rangoon, and also by that of tar de- 
rived from beech wood. It is a fatty substance, without taste or odor, 
and burns with a pure white flame. 

Eupione differs from the preceding compound only in containing a 
smaller portion of carbon. It is obtained by distillation of the tar 
derived from bones or horns. It is a tasteless, inodorous liquid, similar 
to oils, but as limpid as alcohol. 

Naphtha (Symb. 6C-f- 5H. Equiv. 36.72 + 5 = 41.72. Sp. gr. 
0.753) is obtained from coal tar by distillation. It is a volatile, limpid 
liquid, of a strong, peculiar odor, and generally of a light yellow color, 
It is very inflammable, burning with a white flame and much smoke, 
It is used to preserve potassium. 

Naphthaline (Symb. C 10 H 4 . Equiv. 61 . 2 + 4=65.2) is obtained in 
the same manner as the preceding compound. It is a white, crys- 
talline solid, heavier than water, has an aromatic pungent taste, and 
faintly-aromatic odor. With sulphuric acid, it forms a compound, first 
described by Faraday in 1826, under the name of sulpho-naphthalic acid % 
which has a bitter taste and acid properties. 

Paranaphthaline (Symb. C 15 H 6 . Equiv. 91.8 + 6 = 07.8) is allied 
to the preceding, and obtained from coal tar. 

Idrialine is also similar, and obtained from a mineral in the quick- 
silver mines at Idria, in Carniola. 

Campkene and Citrene. Symb. C 10 H 8 . Equiv. 61.2 + 8 = 695. 
Camphene is the basis of camphor ; colorless, volatile, and inflammable 
odor like the oil of turpentine. Citrene is almost the sole ingredient 
of the cil of lemons. 

Gas Lights. 

History. The gas, now so generally employed for th<» 
purpose of lighting cities, is probably a mixture of several o. 



Gas Lights. 193 

the preceding substances, composed mostly, however, of 
olcfiant gas. This gas was first employed tor the purposes of 
illumination by Dr. Clayton, in 1739, but was soon given up 
for more than sixty years. The subject was investigated, 
about fifty years since, by Mr. Murdock ; and since that time 
gas lights have come into general use, both in Europe and 
America. The gas was obtained chiefly from the distillation 
of coal ; but that obtained from oil (spermaceti is the best) is 
much purer, and possesses a greater illuminating power. 
Gas from rosin is about equal to that from oil. 

Process. When oil is used, several large cylindrical cast- 
iron retorts are laid across a furnace, and partially filled with 
brick and bits of iron, to increase the heated surface. The 
oil is contained in a reservoir, and conveyed to the retorts by 
separate tubes. When the retorts are heated to the proper 
temperature, the oil is admitted by a stop-cock, in a small 
stream, so that it is immediately decomposed, and the gas 
passes out of the retorts by other tubes, running into a large 
one, which conveys it to the gasometer.* 

When coal is used, the process is similar : the gas needs 
to be purified by passing it through lime water, to deprive it 
of carbonic acid and other impurities, which give it a very 
disagreeable odor; 112 pounds of coal yield from 450 to 500 
cubic feet of gas ; sp. gr. 0.450 to 0.700 ; and J a cubic foot 
of gas per hour is equivalent to a candle, six to the pound, 
burning during the same time. But oil gas, though much 
more expensive, possesses nearly twice the illuminating power 
According to Henry, it requires vessels and tubes of but half 
the size. 20 cubic feet of coal gas, or 10 of oil gas, is equal 
to a pound of tallow. f 

Portable Gas. In consequence of the greater cheapness 
of gas lights, as compared with candles and oil, it seemed 



* The gasometer is made of iron, in some cases 40 feet in diameter 
and 20 feet high, containing 20,000 cubic feet. This is immersed in 
a vat containing water, and the air permitted to escape by a valve in 
the top. When it is rilled with water, the gas from the large pipe is 
conducted to the bottom, and passes up through the water into the 
gasometer, which rises as fast as it is filled. The gas is now con- 
veyed in a cast-iron pipe, laid under ground, to which small pipes are 
attached, branching off to every part of the city where it is wanted. 

t Coal gas costs about two thirds as much as oil gas, and about on© 
fifth as much as spermaceti candles. 
9 



1 94 Carbon. — Fire-Damp. 

desirable to contrive some method by which it could be made 
portable. This object has been effected by what are called 
'portable lamps. The gas, by means of a forcing-pump, is 
compressed into strong brass globes, and ignited as it escapes 
through an aperture which is furnished with a stop-cock to 
regulate the quantity. These can be carried about like com- 
mon oil lamps. For this purpose, the gas obtained from rosin 
is employed. 

Fire-Damp. This term is applied to several gaseous com- 
pounds of carbon and hydrogen, which are produced in the 
mines of bituminous coal. It is mostly light carbureted hy- 
drogen, and was generated in the original process of forming 
the coal. It issues from various parts of the coal beds, in 
such quantities as to render the whole atmosphere of the mines 
explosive, and often irrespirable. Hence the miners were 
exposed to frequent explosion, and to suffocation. Many ex- 
plosions have occurred in the coal mines of England : the 
older mines extend miles under the ground, and, in some 
cases, are several hundred feet deep. As the gases are 
lighter than the air, they rise and mingle with the air near 
the top, and gradually descend until they reach the miner's 
lamp, when the whole is instantly exploded.* In conse- 
quence of the great expense of human life, and the constant 
fear of the miners, Sir H. Davy undertook the investigation 
of the subject for the purpose of inventing some means of 
safety. He went with the miners into the region of the fire- 
damp, obtained specimens of the gas, and subjected it to 
chemical examination. Ke found that the most explosive 
mixture was 1 part of gas to 7 or 8 of air ; 5 or 6 volumes of 
air would explode but feebly, and above 14 volumes of air to 
1 of gas did not explode at all. It was also found that it re- 
quired the heat of flame to explode it. Iron at a red heat, 
and even at a white heat, would not affect it. But the fact 
which led immediately to the invention of the safety lamp, 
had been observed by Dr. Wollaston, that " an explosive mix« 
tare cannot be kindled through a glass tube so narrow as ^ of 
an inch in diameter." It was also noticed that the mixture 
could not be exploded through fine wire sieves, or gauze 
wire, which acts on the same principle as longer tubes. 

* In 1812, an explosion occurred in Felling colliery, in Northumber- 
land, by which ninety-two men lost their lives. The explosion was* 
heard three or four miles ; thirty-two persons only were saved alive 
In 1815, a similar occurrence happened at Durham, and destroyed 
fifty -seven persons j and in another, twenty-two lost their live? 



Carbon. — Safety Lamp. 



195 




Fig. 87. 



Fig. 86 

h,xp. Place the gauze 
wire a (Fig. 86) over a jet 
Df the gas ; the flame may 
be pressed down, and will 
not pass through the wire. 

Exp. Let a stream of 
the gas pass through the 
wire c ; the gas may be ig- 
nited on the top of the 

wire, but will not communicate through it to the tube 
b. The same is true of flame,* by whatever substance 
it is produced. The wires conduct off the heat, so 
that they do not gain the temperature requisite to 
ignite the gas. 

Safety Lamp. This consists simply of a 
common lamp, a, (Fig. 87,) with a gauze wire, 
b, surrounding the flame. The wire should 
have at least 625 apertures to the square inch. 
Furnished with this lamp, the miners can 
enter the mines in perfect safety from explo- 
sion, but are exposed to suffocation, when 
there is not sufficient oxygen in the mines to 
support the combustion of the oil. 

To enable the miner to escape from the 
mine when the atmosphere becomes such 
as to extinguish the flame of the lamp, a 
platinum coil may be inserted around the 
wick. Thus, in the lamp b, (Fig. 88,) let 
a platinum coil a be inserted around the 
wick ; when the flame ceases, the combus- 
tion will continue slowly for hours, so as 
to heat the platinum red-hot. This will 
give sufficient light to enable the miner to 
escape. 

This is founded on the fact, that plati- 
num wire or foil will, if heated, cause certain gases to com- 
bine gradually, with the production of a red heat, but with- 
out flame. 

Exp. Pour a small quantity of ether into the lamp, and, having 
heated the coil of platinum, plunge it into the ether ; the heat, of the 
wire will cause the vapor of ether and the oxygen of the air to com- 

* The flames of candles, lamps, gas lights, &c, are hollow, as may 
be shown by holding a plate of glass over them. Flames formed by a 
mixture of oxygen with the combustible are solid : hence the use of 
the blowpipe, bellows, &c, to render the flame solid and increase the 
heating power. 




196 Carbon and Nitrogen. 

bine, so as to keep the wire red-hot, and sometimes even at a white 
heat, when the ether will burst into a flame 

Carbon and Nitrogen. 

Bicarburet of Nitrogen, or Cyanogen. Symb. NC 2 or Cy, 
Equiv. 14.15 + 12.24 = 26.39. Sp. gr. 1.804, air=l 

History. This gas was discovered in 1815, by Gay Lussac 
It is sometimes called nituret of carbon, but bicarburet of 
nitrogen expresses definitely its composition. 

Process. It is obtained from the bicyanide of mercury, 
by heating the salt in a small glass retort, with a spirit lamp. 
The retort should be covered with lute, to prevent its 
melting. At a red heat, it is decomposed. The cyanogen 
passes over in the form of a gas, and the mercury is sublimed, 
and remains in the neck of the retort in small globules. 
Collect over mercury or air. 

Properties. This gas is colorless, with a strong, pungent 
odor ; not a supporter of combustion, but burns itself with 
a beautiful purple flame, resembling the peach blossom 
Water, at the common temperature and pressure, absorbs 4J 
times its volume, and alcohol 25 times its volume. At the tem- 
perature of 45°, and under a pressure of 3.6 atmospheres, it is 
condensed into a limpid liquid, but resumes the gaseous 
state when the pressure is removed. The most remarkable 
chemical property of this substance is, that it acts like a 
simple body in most of its combinations, forming substances 
consisting of three elementary bodies, analogous to those 
formed in other cases by two. 

Cyanic Acid (Symb. Cy + O. Equiv. 26.39 +8 = 34.39) 
may"be obtained by exposing cyanuric acid to a dull red heat. 
It has a penetrating odor, pungent, and caustic to the skin, 
producing great irritation of the eyes ; very volatile, giving 
off an inflammable vapor. 

Fulminic Acid. This is isomeric with the preceding, i. e., 
identical in composition, but possessed of different properties. 
It is called fulminic because its compounds of mercury and 
silver are highly explosive. 

Cyanuric Acid (Symb. Cy 3 6 H3. Equiv. 130.17) was 
obtained by Serullas by gently boiling bichloride of cyanogen 



Compounds of Carbon. 197 

in water: cyanunc and hydrochloric acids are the results. 
The hydrochloric is removed by evaporation, and the cyan- 
uric deposited, on cooling, in oblique rhomboidal crystals. 
The crystals are further purified by solution and evaporation. 
Paracyanuric Acid is identical in composition with the 
preceding, but different in properties; it results from the 
spontaneous decomposition of hydrous cyanic acid. 

Chloride of Cyanogen. Symb. Cy-|- CI. Eq. 61.81. First obtained 
in a pure state by Serullas, in 1829, by exposing bicyanuret of mercury 
in powder, and moistened with chlorine gas in a well-stopped vial. It 
congeals at zero in needle-shaped crystals ; is liquid between 5° and 
10°. but above this it is a colorless gas, of a very offensive odor, irri- 
tating to the eyes, corrosive to the skin, and highly injurious to ani- 
mal life. 

Bichloride of Cyanogen. Symb. Cy-\-2Cl. Eq. 97.23. Discovered 
also by Serullas, by putting 155 grains of pure hydrocyanic acid into a 
bottle containing sixty cubic inches of dry chlorine, and exposing it to 
the solar rays. The acid is vaporized, and, in the course of a few 
hours, a colorless liquid is formed on the surface of the bottle, gradu- 
ally growing thicker, until, in the space of twenty-four hours, it sets 
into a white solid, with shining crystals. This is the bichloride of 
cyanogen. It is exceedingly poisonous, caustic to the taste, and pene- 
trating odor, similar to the chloride. 

Bromide of Cyanogen is similar to the preceding. 

Hydrocyanic Acid, or Prussic Acid, (Symb. Cy -}-H 
Equiv. 26.39 -\- 1= 27.39,) was discovered by Scheele, in 
1762. Berthollet afterwards ascertained that it was a com- 
pound of carbon, nitrogen, and hydrogen ; but it was first 
procured in a pure state by Gay Lussac. 

Process. The best process is that of Vauquelin. Fill a 
narrow tube, placed horizontally, with fragments of bicyan- 
uret of mercury, and then pass a current of dry hydrosul- 
phuric acid gas very slowly through it. Double decomposi- 
tion ensues as soon as the gas comes in contact with the 
bicyanuret, when hydrocyanic acid and bisulphate of mercury 
are formed. When the bicyanuret becomes black, the acid 
is expelled by a gentle heat, and collected in a receiver sur- 
rounded with ice. 

Properties. It is a limpid, colorless liquid, of a strong, 
but agreeable odor, similar to that of peach blossoms. It 
excites, at first, a sensation of coolness on the tongue, which 
:s soon followed by heat; but, when diluted, it has the flavor 
of bitter almonds; exceedingly volatile; boils at 79°, and 



S98 Sulphur. 

congeals at zero; unites with alcohol and water in ail 
proportions, but possesses very feeble acid properties. 

It is a most virulent poison. A single drop, if placed on 
the tongue of a dog, causes instant death. A girl swallowed 
a small quantity of it diluted with alcohol, and fell instantly, 
as if struck with lightning, and died in two minutes. 

A professor of Vienna put drops upon his arm, and was 
deprived of life in a few minutes. But though a most potent 
poison in its pure state, when much diluted, it has been em- 
ployed as a medicine, in cases of consumption, with beneficial 
effects. This, like many other violent poisons, cannot be 
employed for criminal purposes, without the almost certain 
risk of being discovered. It exists in the laurel, peach, and 
in beef-steak. 

Sect. 9. Sulphur. 

o u o tt> • ( by vol. 16.66. Q C 6.6558 Air =1. 

Symb. S. Equiv. £ & wgL 16 -, Sp. gr. J j 99 Water==L 

Sulphur has been known from the remotest antiquity. 

Natural History. It exists in nature, in a pure state, in 
the vicinity of volcanoes. It collects in the craters, either in 
fine powder or in crystalline solids ; but it exists more abun- 
dantly in combination with the metals, forming the sulphurets 
of iron, copper, lead, silver, etc., from which it may be sub- 
limed by heat, but is not quite pure. It is found also in many 
mineral waters ; in many minerals, such as gypsum, sulphate 
of strontia, etc. ; in all animals, and some plants. 

Process. The sulphur of commerce exists in two states ; 
in rolls, called roll brimstone, and in fine powder, called flow- 
ers of sulphur ; but the two varieties are readily resolved into 
each other by the application of heat. 

Exp. Heat a brick, or small iron cup, to nearly a red heat. Place 
upon' it roll brimstone, and invert over it a bell-glass receiver ; the 
sulphur will sublime* i.e., pass into a fine powder, like vapor, and col- 

* This may serve to illustrate the process of sublimation as applied 
to other substances. Camphor and gum benzoin are easily sublimed 
The process of converting mercury into vapor, and condensing it, is 
also called Bublimation, although it is a liquid. 



Sulphur. — Properties. 



199 



lec on the sides of the vessel. In this way the flowers of sulphur are 
prepared. 

Properties. Sulphur is a brittle solid, of a lemon-yellow 
iolor, nearly tasteless, and inodorous, except when rubbed or 
heated. It is a non-conductor of electricity, but becomes neg- 
atively electrified by friction ; fuses at 216° Fahr. ; possesses 
the highest degree of fluidity between 230° and 280°, and is 
of an amber color; at 320°, it begins to thicken, acquiring a 
red tint; between 423° and 482°, it is so tenacious as to re- 
main in the vessel when inverted ; but, from 482° to its boiling 
point, it grows fluid again, and sublimes rapidly from 550° to 
600° Fahr. 

Wlien cooled from the several temperatures above named, it 

possesses different degrees of consistency. Cooled suddenly 

from the most fluid state, it is hard and brittle ; but if plunged 

into cold water between the temperatures of 320° and 482°, 

it is soft, and may be drawn out like wax; cooled from the 

boiling point, it is of a deep red-brown color, very soft and 

transparent. It is prepared in this way for taking seals. 

The native crystals are octohedrons, with rhombic bases; 

those formed artificially occur in oblique rhombic prisms 

Exp. Melt a few pounds of sulphur in an 
earthen crucible,* (Fig- 89.) and, when it is 
partially cooled, pierce the crust so that the 
fluid parts may flow out; on breaking the 
mass when cooled, the interior will exhibit a 
cluster of beautiful crystals. Fig. 89 rep- 
resents a section of the crucible containing 
Xae sulphur after it has cooled. 

Sulphur is soluble in boiling oil of 
turpentine, which is a test of its puri- 
ty. Sulphur is highly combustible ; it 
burns with a pale blue flame, and com- 
bines readily with the metals. 

Exp. Mix copper or iron filings with sulphur, and heat them in 



Fig. 89. 




gla^s tube, or crucible, by a spirit lamp 
auid form sulphurets of these metals. 



The sulphur will combine, 
rets or these metais. 

Impurities. Sulphur contains some hydrogen in its purest 



* There are four principal varieties of crucibles : — 1. Wedgwood crt*' 
tibles are made of a mixture of burned and unburned clay j 2. Black 



200 Sulphur. — Sulphurous Acid. 

state; but the more common ingredients are earthy sub« 
stances and arsenic ; the latter is tested by ammonia. 

Uses. Employed extensively in the manufacture of gun* 
powder, for seals, medallions, and as a cement for iron. 
Used in medicine, for the diseases of the skin, humors, etc. 
The milk of sulphur, which is sulphur combined with water, 
and precipitated from some of its alkaline solutions by an 
acid, occurs in a gray powder, and is sometimes used in 
medicine. 

Hyposulphurous Acid, Symb.2S + 20. Eq. 32.2+16 = 
48.2. It is difficult to procure this in a pure state. It may 
be formed by digesting sulphur in a solution of any sulphite. 
It is distinguished by uniting with the oxide of silver, which 
separates the acid from soda. 

Sulphurous Acid. Symb. S + 20 or SO 2 . Eq. 16.1 + 
16 = 32.1. Sp. gr. 2.2117, air = l. 

History. Sulphurous acid appears to have been known 
from an early period. v Stahl first pointed it out as a distinct 
substance ; but its discovery in a pure state was made by 
Priestley, in 1774, and accurately analyzed since, by Gay 
Lussac and Berzelius. It exists in nature in the vicinity of 
volcanoes, and issues from the fissures in the craters, and 
from the lava, often in immense quantities. 

Process. Burn sulphur in common air, or in dry oxygen 
gas, over mercury ; but the best method is to put 2 parts 
of mercury and 3 of sulphuric acid into a retort, and 
apply the heat of a lamp, and collect over mercury. 

Theory. The sulphuric acid has 3 equiv. of oxygen, one of which 
smites with the mercury, forming the oxide of mercury, which com- 
bines with some undecomposed sulphuric acid, and forms the sul- 

lead crucibles are formed by a mixture 
of clay and plumbago ; 3. Hessian 
crucibles are composed of a mixture 
of sand and clay ; 4. Metallic cruci- 
bles are made of silver, platina, &c. 
These latter are used with the spirit 
lamp in analytical processes. The 
form of these vessels is represented 
in Fig. 90. Metallic and porcelain 
crucibles are generally provided with 
covers and stands, as in the figure, 
but the best stand is a piece of fire- 
brick 




Sulphurous Acid. 201 

phate of mercury, which remains in the retort, and the sulphurous acid 
comes over in the gaseous state. The gas is heavier than the air, and 
can be collected in a manner described on page 139, fig. 04. 

Properties. A transparent, colorless gas, sour to the 
taste, and pungent, suffocating odor, by which it is distin- 
guished from all other gases ; extinguishes burning bodies, 
but is not combustible. 

Exp. A candle immersed in a jar of this gas is instantly extin- 
guished. 

It is irrcspirable, and fatal to animal life. When largely 
diluted with air, it excites coughing, and uneasiness about 
the chest ; when perfectly pure, it excites spasms of the glot- 
tis, which prevent its introduction into the lungs ; of course, 
an animal confined in it is instantly suffocated. 

It reddens vegetable colors, and then discharges them. 

Exp. Place a rose over an ignited sulphur match in the open air, 
and it will turn white ; hence it is used for bleaching straw, silk, and 
for removing fruit-stains from woollen cloths, etc. 

It has a strong attraction for zoater and oxygen. Water 
absorbs it so rapidly, that, if ajar of the gas be inverted over 
it, the atmosphere will force the water into the jar with great 
violence ; recently-boiled water absorbs 33 times its volume. 

Sulphurous acid will remain with dry oxygen without 
change, but if water be present, it combines with oxygen, 
and forms sulphuric acid. It instantly decomposes those 
oxides, the metals of which have a weak affinity for oxygen, 
such as those of gold, platinum, and mercury. Nitric acid 
yields to it one proportion of oxygen, and converts it to sul- 
phuric acid. 

liquid Sulphurous Acid. It becomes liquid by the pres- 
sure of two atmospheres, and even by surrounding it with a 
freezing mixture. In this state it is anhydrous, a little 
heavier than water, (sp. gr. 1.45,) and boils at 14° Fahr. 

By its evaporation, it produces so intense a degree of 
cold, that mercury may be frozen, and several of the gases 
rendered liquid. 

Exp. Pour liquid sulphurous acid upon water contained in a shal- 
9* 



202 Sulphur. 

low vessel ; the acid will boil, and its vapor will absorb so much 
caloric that the water will soon be frozen. 

Exp. Or pour it upon mercury in a shallow dish, and place it undei 
the exhausted receiver of an air-pump ; the mercury itself will soon 
congeal. 

It may be obtained in the solid form in crystals containing 
water, by passing the moist gas through a receiver, cooled 
from 50° to 14° Fahr. 

Uses. Sulphurous acid is often employed for bleaching 
purposes, for whitening straw and silks, and for the barbarous 
purpose of killing bees. 

Hyposulpliuric Acid, Symb. 2S + 50. Equiv. 32.2 + 40 

= 72.2. This acid was discovered in 1819, by Welter and 
Gay Lussac. 

Process. It may be formed by passing sulphurous acid 
gas through water containing peroxide of manganese. By 
the interchange of elements, the sulphate of the protoxid and 
the hyposulphate of the protoxide of manganese are formed; 
the latter remains in solution. The manganese is thrown 
down by pure baryta, and the hyposulphate of baryta ob- 
tained, which crystallizes by evaporation, and is then decom- 
posed by sulphuric acid, by which the sulphate of baryta is 
precipitated, and hyposulphuric acid remains in solution. 

Properties. Colorless, inodorous, sour to the taste, red- 
dens litmus, and cannot be wholly freed from water. 

Sulphuric Acid. Symb. S + 30, SO 3 , or S. Equiv. 16.1 
-(-24 = 40.1. Sulphuric acid was discovered by Basil 
Valentine, near the close of the fifteenth century. It is 
commonly called oil of vitriol, because it was first obtained 
by the distillation of green vitriol, (sulphate of iron or cop- 
peras.) It exists in nature abundantly in the sulphate of lime 
(gypsum.) 

Process. Anhydrous sulphuric acid may be obtained from 
the hydrous acid, manufactured at Nordhausen, in Germany, 
from the protosulphate of iron, and called fuming sulphuric 
acid. But the best method is that of Professor Mosander, o f 
Stockholm. — Saturate the oxide of antimony with excess of 
sulphuric acid, and then, by a slow heat, drive off the excess 



Sulphurous Acid. 203 

cl acid, when the salt will crystallize as a dry sulphate of 
antimoin . Expose this salt to a dull red heat in a retort, and 
the anhydrous acid will be driven off, and may be collected 
in a dry receiver, surrounded with ice. 

Properties. In this state, the acid has some peculiar prop- 
erties. It is a white, opaque solid ; fuses at 66° Fahr. ; sp* 
gr. 1.99 ; boils between 104° and 122°, forming a transparent 
vapor ; has a powerful affinity for water, so that, on exposing 
it to the air, it flies off in white fumes, forming 4 definite 
compounds with water, which are thus constituted: 

2SO*+HO S0 9 -fHO SO*+2HO S0 3 4-3HO 

Exp. Burn a mixture of 8 parts of sulphur to 1 of nitre in a vessel 
»f oxygen gas containing a vegetable infusion; the aeid will be ab- 
sorbed by the water, and change the infusion red. 

But the process for manufacturing this acid in the arts, is 
done in chambers lined with sheet lead* 8 parts of sul- 
phur to i of nitre, coarsely bruised and mixed together, 
are put upon iron plates, 1 lb. to 800 cubic feet of air. The 
mixture is ignited by a hot iron, and the door closed. Water, 
to the depth of 6 inches, covers the floor, and absorbs the 
acid as fast as formed. The room is then ventilated, and the 
process repeated every four hours, until the water is suffi- 
ciently acid ; or, by an improvement in the structure of the 
room, the sulphur is burned in a separate room, and the air, 
admitted continually, carries the acid vapor into the chamber, 
where it is condensed by the water. This acidulated water 
ts then drawn off and concentrated by heat, in leaden boilers, 
until it is of the specific gravity 1.450, and the concentration 
ts finished in glass or platinum dishes placed in sand baths. 

Theory. By the combustion two gases are formed — sulphurous acid 
from the sulphur, and binoxide of nitrogen from the nitre. The latter 
combines with the oxygen of the air, and is converted into the nitrous 
acid. The sulphurous and nitrous acids then combine with the watery 
vapor, and form a crystalline solid, composed of sulphuric acid, hyponi- 
tro'ui acid, and water. When this solid drops into the water, it is 
instantly decomposed, the sulphuric acid is retained in the water, and 
nitrous acid and binoxide of nitrogen escape. The nitrous acid thus 
.get free, as well as that formed by the binoxide and oxygen of the air, 
again combines with the moist sulphurous acid, and forms the solid, 
whieh sinks to the water, and is decomposed again. This process con- 



* The usual sjz;e of the chamber is 20 feet long, and 12 wide ; but 
in one establishment in England, the chamber is 120 feet by 40, and 20 
liigi;. containing 96,000 cubic feet, 



%04 Sulphur. 

tinues, until the whole is converted into sulphuric acid, and absorbed 
by the water. 

Properties. Hydrous sulphuric acid, when pure, is an 
oily, limpid liquid, colorless, inodorous, intensely sour and 
corrosive ; destroys, by the aid of heat, all animal and vege- 
table bodies, with the deposition of charcoal, and formation 
of water ; hence the acid often attains a hroivn tinge by 
charring substances which accidentally fall into it ; boils it 
620° Fahr., and freezes at -15°. When its specific gravity is 
1.78, it congeals above 32°, and remains solid up to 45° ; 
but when mixed with twice its weight of water, it congeals 
at -38°. 

It has a powerful affinity for water. It combines with 
the water of the air, even at boiling temperatures, so power- 
fully that its greatest concentration can be effected only by 
glass or platinum retorts with narrow mouths. 

Exp. 4 parts of sulphuric acid and 1 of water, each at 50°, when 
poured together, have a temperature of 300°. The heat is occasioned 
by the diminution of hulk, by which the insensible caloric becomes free. 

Exp. 2 parts of acid and 3 of snow form a mixture which will 
freeze water, and the thermometer will sink even to -23°. The cold 
results from its affinity for water ; it dissolves the snow to obtain it j 
and the heat necessary to render the water liquid is absorbed from the 
acid and the snow, and passes into an insensible state. 

Exp. 1 part of snow to 3 of acid will produce a heating mixture, 
because the condensation develops more heat than is required to melt 
the snow. 

The decomposition of sulphuric acid is effected by heat k 
and by the non-metallic combustibles. 

Exp. Pass hydrogen gas and sulphuric acid through a red-hot por 
celain tube. 

Exp. Heat this acid with charcoal, or put into it vegetable sub- 
stances. 

Exp. Expose the acid to the galvanic battery ; the sulphur ynll 
appear at the negative, and the oxygen at the positive pole. Its spe- 
cific gravity never exceeds 1.9. 

Its strength is tested by its specific gravity, and by the 
quantity required to saturate a given portion of an alkali. 
100 grains of the carbonate of soda will neutralize 92 of 
pure sulphuric acid. It may be detected in any solution by 
the chloride of barium, by which a white, insoluble solid is 
precipitated — the sulphate of baryta. 



Sulphur and Hydrogen. 205 

It is one of the most powerful of acids, reddens the vege- 
table infusions, unites with bases, and forms salts, which are 
called sulphates. 

It is a most violent poison. The best antidote is dry mag- 
nesia. If water be taken, it will produce a very great heat, 
and thus increase its injurious effects. 

Uses. It is one of the principal acids of chemistry and 
of the arts, in which greater quantities are employed than 
of any other acid ; for the formation of most of the other 
acids ; for the preparation of soda from salt, of alum from 
sulphate of iron ; for obtaining chlorine and other gases ; for 
dissolving indigo for dyes. It is used in medicine as a tonic. 

Bichloride of Sulphur (Symb. 2S + C1. Eq. 67.62. Sp. gr. 1.687) 
was discovered by Dr. Thompson, in 1804. Prepared by passing a 
current of chlorine gas over flowers of sulphur, gently heated, till 
nearly all the sulphur disappears. The dichloride is then obtained by 
distillation in the form of a reddish liquid. 

Iodide of Sulphur. First described by Gay Lussac. Formed by 
heating 4 parts of iodine with 1 of sulphur. A dark-colored substance, 
easily decomposed by heat. 

Bromide of Sulphur is obtained by pouring bromine on sublimed 
sulphur. The product is an oily liquid, of a reddish tint; odor resem- 
bles the dichloride of sulphur. 

Sulphur and Hydrogen. 

Hydrosulphuric Acid. Symb. SH. Equiv. 16.1 — |— 1 =: 
17.1. Equiv. vol. 100. Sp. gr. 1.1782, air = 1. This sub- 
stance was discovered by Scheele, in 1777, and has been 
variously named, sulphureted hydrogen and hydrothionic 
acid. 

Process. It may be obtained from the sulphurets of the 
metals. The one generally employed is the protosulphuret 
of iron, which is a native product, but can be prepared by 
heating 2 parts of iron filings with 1J of sulphur to a red 
heat, in a covered crucible ; upon this, in a retort, pour dilute 
sulphur c acid, apply gentle heat, and collect over water. 
Sesquisulphuret of antimony, treated in the same manner 
with hydrochloric acid, will yield a purer gas ; the former 
contains a little iron and hydrogen. 

Tluory. The oxygen of the water unites with the iron, and ita 
hydrogen with the sulphur, and the sulphuric acid unites with the 
wide of iron ; the products are hydrosulphuric acid and sulphate of 



208 Sulphur and Hydrogen. 

the protoxide of iron. FeS, SO 3 and HO aire Converted into SO 3 -+ 
FeO, and SH. 

Properties. It is a colorless gas, but has an excessively 
offensive taste and odor ; it is this gas which gives the odor 
to putrescent eggs, sewers, and the waters of sulphurous 
springs. It extinguishes burning bodies, but burns with a 
pale blue flame; forms an explosive mixture with oxygen, 
and is so destructive to animal life that T -^\^ part of this gas 
in air destroys small birds ; ¥t ^- part killed a middle-sized 
dog, and ^--i^ part a horse. If placed on the cutaneous 
surface of animals, it will prove fatal to them. Reddens lit- 
mus feebly, but unites with bases and forms salts. 

Water absorbs 3 volumes of the gas, and forms a colorless 
liquid, similar to the gas in taste and odor. This water is a 
test of the metals. Nitric acid will cause a precipitate of 
sulphur ; and if poured into a bottle of the gas, a blue flame 
will pervade the vessel, and sulphur and nitrous acid fumes 
be produced. If exposed to the air, it deposits its sulphur 
on the surface of the vessel ; but it is readily decomposed by 
metals in solution ; the sulphur combines with the metal, and 
the hydrogen is liberated. 

It is also decomposed by chlorine and iodine, because of 

their great affinity for hydrogen. Hence chloride of lime is 

used to purify places rendered noxious by this gas. It is 

partially decomposed by heat, in a porcelain tube. 

Liquid Hydrosulphuric Acid. Mr. Faraday succeeded in condensing 
the gas. Under a pressure of 17 atmospheres, it is colorless, limpid, 
and excessively fluid ; compared with it, ether appears tenacious and 
oily. On breaking a tube under water, it rushed out violently, and 
assumed the gaseous state. 

Test. The best test of this gas is carbonate of lead. 1 
part of the gas mixed with 20,000 of air will give a brown 
stain to a surface whitened with the lead. Hence persons 
who use preparations of lead to improve their beauty, on 
coming into the vicinity of this gas, often change their color, 

Exp. Write on paper with any of the salts of lead in solution, and 
pass a stream of the gas over it ; the writing will instantly appear. 

Uses. In medicine for cutaneous eruptions, in the labora- 

tory as a test of metals ; hence its use in analytical processes, 



Sulphur and Carbon. 



207 



Production of Sulphur in Volcanoes by the Meeting of Sul- 
phurous and Hydrosulphuric Acids. Those acids are gener- 
ated in volcanoes, and, as they meet, are decomposed, and 
sulphur is deposited. This may be shown in the following 
manner : — 

Let two small retorts Fig. 91. 

a, a, (Fig. 91,) pass into 
a globe receiver, b, so 
that their mouths shall 
nearly touch each other. 
Put the materials for sul- 
phurous acid into one, 
and for hydrosulphuric 
acid in the other, and 
apply heat; as the two 

gases meet in the receiver, they will be decomposed, and the 
sulphur will be deposited upon the interior surface, in fine 
powder. 

Hydrosulphurous Acid. Symb. 2S-J-H. Equiv. 33.2. Discovered 
by Scheele, who called it super sulphur eted hydrogen. The names 
hydrothlonous acid, per or bisulphureted hydrogen, and persulphuret of 
hydrogen, have also been applied to it. 

It is similar in taste and odor to hydrosulphuric acid, but not so 
powerful ; semi-fluid, inflammable, and easily decomposed by heat into 
sulphur and hydrosulphuric acid. 




Sulphur and Carbon. 

Bisulphuret of Carbon, or Alcohol of Sulphur, Carbosul- 
phuric Acid. Discovered accidentally by Professor Lampa- 
dius, in 1776 ; but its true nature was first pointed out by 
Clement and Desormes. 

Process. It is obtained by heating, in a close vessel, the native 
bisulphuret of iron {iron pyrites) with one fifth of its weight of dry 
charcoal. " The compound, as it is formed, should be conducted, by 
means of a glass tube, into a vessel of cold water, at the bottom of which 
it is collected. To free it from moisture and adhering sulphur, it should 
be distilled at a low temperature, in contact with chloride of calci- 
um." — T. 

Properties. A transparent, colorless liquid, remarkable 
for its high refractive power, acid, pungent, and somewhat 
aromatic taste, and fetid odor; specific gravity, 1.272, ex- 
ceedingly volatile; boils at 110°; very inflammable, and 
burns with a pale blue flame. With oxygen, its vapor forms 
an explosive mixture ; with hiuoxida of nitrogen, it forms a 



S08 Cyanogen and Sulphur. 

mixture which burns with dazzling brilliancy ; dissolves ia 
alcohol and ether, and is precipitated by water ; dissolve! 
phosphorus, sulphur, and iodine, giving to a solution of the 
latter a beautiful pink color. It is decomposed by chlorine, 

Cyanogen and Sulphur. 

Sulphur et of Cyanogen was discovered in 1828, by M. Lassaigne, by 
the action of bicyanuret of mercury, in fine powder, upon half its 
weight of bichloride of sulphur, confined in a small glass globe, and 
exposed for two or three weeks to daylight. A small quantity of crys- 
tals, biting to the tongue, and of a penetrating odor, collected in the up- 
per part of the vessel, which form red-colored compounds with per 
salts of iron. 

Bisulphuret of Cyanogen (Symb. 2S-f- Cy) was discovered by Liebig, 
by exposing fused sulphocyanuret of potassium to a current ofdry chlo- 
rine gas ; it forms a dry, yellow powder. 

Hxj&rosulpho cyanic Acid. Symb. S 2 CyH. Equiv. 59.59. Dis- 
covered in 1808, by Mr. Porritt, who ascertained it to be a compound 
of sulphur, carbon, hydrogen, and nitrogen. It is sometimes called 
sulphocyanic acid, and may be formed by suspending sulphocyanuret 
of silver or mercury in water, and by transmitting through it a current 
of hydrosulphuric acid gas; sulphuret of silver or mercury, and hydro- 
sulphocyanic acid, are generated; filter the solution, and expel the 
excess of gas by heat. 

Properties. A liquid, either colorless, or a shade of pink; 
odor resembling vinegar ; sp. gr. 1.002 ; boils at 216^5° ; crys- 
tallizes in six-sided prisms at 45.5° Fahr. ; acid to the taste, 
and by the chemical tests. It also unites with alkalies. 

Test of its Presence. A salt of the peroxide of iron, to 
which it gives a deep blood-red solution ; decomposed by 
exposure to the air, and by chloric or nitric acid. 

Cyanohydro sulphuric Acid (Symb. S 2 CyH 2 . Equiv. 
60.59) may be obtained by passing a current of hydrosul- 
phuric acid through a saturated solution of cyanogen in alco- 
hol. The liquid acquires a reddish-brown tint, and numer- 
ous small crystals, of an orange-red color, are generated. It 
is considered by Liebig to be similar in composition to ths 
preceding, but to have one equivalent more of hydrogen. 



Sect. 10. Phosphorus. 

u u p v ■ $ by vol. 25. Q C 1.77 Water = 1 

fcymb. P. Equiv. J / wgt> ,g 7 Sp. gr. J 4 3261 Aif = ± 

History. Phosphorus received its name from the property 
of shining in the dark.* 

* tptig, light, and (ptQ^ to carry. 



Phosphorus. 209 

It was discovered by Brandt, an alchemist of Hamburg, in 
1660. It was formerly obtained from urine, but the process 
of obtaining it was for a long time kept secret, and small 
quantities only were procured. Scheele obtained it from 
bones, and invented the method now generally employed. It 
exists in the bones of all animals, in the state of phosphate 
of lime. A middle-sized man has about one pound of phos- 
phorus in his bones. 

Process. The bones are calcined in an open fire, reduced 
to a fine powder, and digested for a few days with one half 
their weight of sulphuric acid, with sufficient water to give 
them the consistency of paste. The phosphate of lime is 
decomposed, and the sparingly-soluble sulphate and soluble 
superphosphate of lime are generated. The latter is then 
dissolved in warm water, filtered and evaporated to the con- 
sistency of sirup. 

It is then mixed with J part of charcoal, in an earthen re- 
tort lined with clay, heated in a furnace to a high tempera- 
ture, when the vapor of the phosphorus comes over, and is 
conducted by a tube into a bowl of waier, where it is con- 
densed into a reddish-brown solid. This is then fused in hot 
water, and distilled in hydrogen, or passed through chamois 
leather. 

Properties. When pure, it is transparent and nearly col- 
orless, or of a wax color ; easily cut with a knife, and the sur- 
face has a waxy appearance and texture; fuses at 108°, and 
at 550° is converted into vapor; soluble by the aid of heat in 
naphtha, in fixed and volatile oils, and in the chloride of sul- 
phur, sulphuret of carbon, and sulphuret of phosphorus. On 
cooling a solution of the latter, it crystallizes in dodeca- 
hedrons. 

It is very inflammable. At common temperatures, it com- 
bines slowly with the oxygen of the air, giving a luminous 
appearance in the dark. 

Exp. If a stick be placed in a receiver of air, it will absorb the oxy- 
gen, and leave the nitrogen. 

Exp. If a stick of phosphorus be dusted over with charcoal or resin, 
and placed under the receiver of an air-pump, it will inflame on ex- 
hausting the air. 

Exp. By friction it instantly ignites, and hence is employed for 
matches. 



210 



Phosphorus. 




Exp. JVken ignited in oxygen, it Fig 1 . 92. 

burns with great brilliancy. This Rg^jIp s^ft^^ B gKaa ^B 
experiment should be conducted 
in a large globe receiver, (Fig. ff 
92,) filled with oxygen, and the 
phosphorus placed in the centre 
by a pendent copper spoon. Dense 
white fumes of phosphoric acid are 
formed ; these often mingle with 
the vapors of phosphorus and oxy- 
gen, which renders the whole in- 
fiammable; and hence the danger 
of breaking the receiver. 

Exp. Let a stream of oxygen 
gas upon phosphorus in a fused 
state, under water, and flashes 
of light will pass up through the 
water. 

Exp. Or put a few grains of chlorate of potassa into a glass of water, 
in which is a piece of phosphorus, and from the dropping tube pour 
on nitric or sulphuric acids; flashes of light will appear. 

Exp. Drop a small piece into a glass containing a small quantity of 
strong nitric acid ; it will burn vividly, and often explode Willi great vio- 
lence. (See Fig. 77.) 

Exp. Sweet oil dissolves it by the aid of heat, and the phosphorized 
oil can be put, on the face and hair so as to render it luminous in 
the dark. 

Theory. In all these cases, the light results from the union 
of phosphorus with oxygen ; so strong is its affinity for oxy- 
gen, that it should always be kept under water. If exposed 
to the air, and held in the hands in a dry state, there is dan- 
ger of its entering into a state of combustion, especially if 
any friction is applied to it. 

Relation to Animals. It is very poisonous; acts as an 
excitant, and in large doses it proves fatal ; but it is used 
sometimes as a medicine. It renders water poisonous in 
which it is kept. 



Phosphorus and Oxygen. 

Oxide of Phosphorus. Symb. 3P -f O. Equi v. 47.1 -f- 8 = 55. 1 . It 
is obtained by burning phosphorus under hot water, by a jet of oxygen 
gas. The substance which remains after combustion is of a red color, 
without taste or odor ; insoluble in water, alcohol, ether, and oil ; is 
not volatilized at 662° Fahr., but takes fire at a low red heat, in the air 
and in chlorine gas. This substance has been examined by M. Pelouse, 
and found to be an oxide of phosphorus. 

Hypophosphorous Acid (Symb. 2P-J-CX Equiv. 31.4 + 



Phosphoric Acid. 211 

8=39.4) was discovered by Dulong, in 1816, and is obtained 
by the action of water upon the phosphuret of barium. Hy- 
pophosphite of baryta is formed soluble in water ; on filtering 
the solution, and adding sulphuric acid to precipitate the 
baryta, the hypophosphorous acid remains, and is concentra- 
ted by evaporation into a viscid liquid, capable of crystalliza- 
tion ; this is the hydrate of the acid, and is a powerful deox- 
idizing* agent. 

Phosphorous Acid (Symb. 2P + 30. Equiv. 31.4+24 = 
55.4) was discovered by Davy, and may be obtained by sub- 
liming phosphorus through the bichloride of mercury, in a 
glass tube; a limpid liquid distils over, which is a compound 
of phosphorus and chlorine. Put this into water, and the 
hydrogen of the water unites with the chlorine, forming hy- 
drochloric acid, and the oxygen of the water combines with 
the phosphorus, forming the phosphorous acid. The solution 
is then evaporated to the consistency of sirup, to expel the 
hydrochloric acid, and the phosphorous acid crystallizes as 
a hydrate. The anhydrous acid may be obtained by burning 
the phosphorus in highly-rarefied air. 

Properties. Sour to the taste, odor like garlic, and pos- 
sesses acid properties ; has a strong affinity for oxygen, and 
is hence easily converted into phosphoric acid ; precipitates 
mercury, silver, platinum, and gold, from their saline solu 
tions, in the metallic form. 

Phosphoric Acid. Symb. 2P + 50. Eq. 31.4 + 40 = 
71.4. Under the term of phosphoric acid, three compounds 
lave formerly been described, affording a remarkable in- 
stance of a class of bodies, called isomeric, which are identical 
in composition, but possess different properties. The names 
given to the three compounds are, phosphoric, pyrophosphoric, 
and meta or paraphosphoric acids. 

1. The Phosphoric Acid has hitherto been obtained only 
in combination with water or an alkaline base. 

Process. The superphosphate of lime is boiled for a few 



* Bodies are said to deoxidize when they abstract oxygen from its 
combinations with other bodies. They are said to oxidize when they 
yield oxygen to other bodies. 



212 Phosphorus. 

minutes with excess of carbonate of ammonia, by which the 
lime is precipitated as a phosphate. After filtration, the liquid 
is evaporated to dryness, and then ignited in a platinum 
crucible, to expel the ammonia and sulphuric acid. 

Properties. Colorless, intensely sour, reddens vegetable 
infusions powerfully, and neutralizes alkalies. In the state 
of greatest concentration, it is composed of three equivalents 
of water, and one equivalent of acid, and may be made to 
crystallize in thin plates. It is remarkable for uniting 
with bases, in the proportion of 1 equivalent of the acid to 
3 of the base, or the oxygen of the base and the acid as 
3 to 5. ' 

2. The Pyrophosplioric Acid is obtained by exposing 
concentrated phosphoric acid to a temperature of 145°. 

Its properties are generally similar to the preceding, but 
it is distinguished from it by yielding a snow-white pre- 
cipitate, when neutralized with ammonia, and mixed with 
the nitrate of the oxide of silver. It is remarkable for its 
tendency to unite with 2 equivalents of a base to 1 of the 
acid. 

3. Meta or Paraphosphoric Acid is obtained by burning 
phosphorus in dry air, or oxygen gas. The acid appears in 
small crystals, like snow, on the interior of the vessel. It is 
formed, combined with water, by heating to redness the two 
preceding acids; when fused, it cools into a brittle and 
transparent solid, resembling ice, hence called glacial phos- 
phoric acid, very deliquescent, and hence must be kept in 
close bottles. It is distinguished from the others by uniting 
1 equivalent of a base to 1 of the acid. 

Phosphorus and Chlorine. 

The Sesquichloridc of Phosphorus (Symb. 2P-f-3Ci. 
Equiv. 31.4 + 106.26=137.66. Sp. gr. 1.45) may be 
formed by passing the vapor of phosphorus over corrosive 
sublimate, in a glass tube, or by heating the perchloride with 
the phosphorus. 

Properties. It is a clear, limpid liquid, not acid by this 



Phosphorus and Hydrogen. 213 

chemical tests, though it emits acid fumes when exposed to 
the air. This is due to the affinity of the chlorine for the 
hydrogen of the water contained in the air. When mixed 
with water, mutual decomposition takes place, with evolution 
of heat, and the formation of hydrochloric and phosphoric 
acids. 

The Per chloride of Phosphorus is formed by the spon- 
taneous combustion of phosphorus in chlorine gas. Symb. 
2P + 5CL Eq. 208.5. 

Properties. A white solid, volatile at a temperature below 212° ; 
heated under pressure, it fuses, and forms, m cooling, transparent, 
prismatic crystals. Thrown into water, mutual decomposition ensues 

Iodides of Phosphorus. There appear to be three com- 
pounds of iodine and phosphorus, produced by the spontane- 
ous combustion of the two substances. 

Tlie Protiodide (Symb. P-|-l. Equiv. 142) has a yellow color, 
fuses at 212°, sublimes by heat unchanged, and is decomposed by 
water. 

The Scsquiodide (Symb. 2P -f 31. Equiv. 410.3) is a dark-gray 
crystalline mass, fuses at 84°. 

Tks Pcriodide (Symb. 2P + 5I. Equiv. 662.9) is a black com- 
pound, fusible at 114°. 

Bromides of Phosphorus are formed by bringing phospho- 
rus and bromine into contact, in a flask filled with carbonic 
acid. 

The Proiobromide (Symb. P -4- Br. Equiv. 94.1) is a liquid formed 
at the bottom of the flask, easily converted into vapor by heat, acts 
energetically upon water, and mutual decomposition takes place. 

The Perbromide (Symb. 2P -|-5Br. Equiv. 423.4) is a yellow solid, 
converted by heat into a red-colored liquid, and into a vapor of a simi- 
lar tint. When cooled from fusion, it yields rhombic crystals. Emits 
dense, penetrating fumes when exposed to the air, and is decomposed 
by water and chlorine. 



Phosphorus and Hydrogen. 

Phosphuret of Hydrogen, (Symb. 2P + 3H. Equiv. 31.4 
-J- 3 = 3-4.4,) called also hyduret of phosphorus, was discov- 
ered in 1812, by Sir H. Davy, by heating hydrated phospho- 
rous acid in a retort. 

Properties. It is colorless, with the odor of garlic ; does 
not take fire spontaneously in air, but instantly inflames in 



114 



Phosphorus. 



chlorine gas, with a white light ; forms with oxygen a del 
onating mixture. 

Perphospkuret of Hydrogen is isomeric with the prece- 
ding. It was discovered in 1783, by Gengembre, and has 
been since examined by Dalton, Thompson, and others. The 
names phosphureted hydrogen and hyduret of 'phosphorus 
have also been applied to it. 

Process. For the purposes of experiment, it is easily 
prepared in the following manner : Fill a pint retort half full 
of recently-slacked lime, and put into it a stick of phosphorus 
two or three inches long, cut into strips. Then pour on a 
strong solution of carbonate of potassa, rilling the retort quite 
full. Place the beak of the retort in the cistern, and apply 
heat.* The gas will soon form and inflame when it comse 
in contact with the air, forming beautiful wreaths of smoke, 
which rise up from the water. Or it may be collected like 
any other gas. 

Properties. This gas is colorless, and has a highly-offen- 
sive odor, and bitter taste ; will neither support flame noi 
respiration. 

Fig. 93. 




cE^i 



Inflames spontaneously when admitted into air f and explo- 
sively with oxygen gas. As the bubbles of the gas (Fig. 93) 
rise through the water in the cistern b into the air, they 
inflame successively, the phosphoric acid and vapor form a 
series of rings, as c, of dense white smoke, continually 



* The readiest mode of obtaining this gas is to heat phosphorus in 
connection with quicklime, forming the phosphuret of lime. Drop 
this into water acidulated with hydrochloric acid. The water is de- 
composed, and its hydrogen and oxygen unite with the phosphorus, 
and form hypophosphorous acid, phosphoric acid, and phosphuret of 
hydrogen 



Boron, 215 

increasing in size as they arise, and producing one o*' the 
most striking and beautiful appearances in experimental 
chemistry. If a bubble of the gas is admitted into a receiver 
of oxygen gas, a bright flash of light is seen, and the receiver 
/s jarred by the concussion. This is one of the most re- 
markable properties of this gas, and distinguishes it from all 
■?ther gases. It is often produced by the decomposition of 
>ones, in swamps and graveyards, and gives rise to those 
ights which are frequently seen about such places. It is the 
'eal " Jack o' the lantern," or " Will o' the wisp." 

Water absorbs one eighth volume of this gas, and, if the gas 
is suffered to remain over water for a few days, it loses its 
spontaneous inflammability, but will inflame on the applica- 
tion of a lighted taper. 

Phosphorus and Sulphur. 

Sulphur et of Phosphorus. The nature of this compound is 
not accurately settled ; it is formed by bringing sulphur in 
contact with fused phosphorus. They act on each other 
with great violence, producing a compound of a reddish- 
brown color, which fuses at 16° Fahr., and is highly combus- 
tible. 

Sect. II. Boron. 
Symb. B. Eq. 10.9. Equiv. vol. 100. 

This substance was discovered in 1807, by Sir H. Davy, 
by exposing boracic acid to a powerful galvanic battery ; but 
its properties were first investigated by Gay Lussac and The- 
nard, who obtained it in greater quantity by heating boracic 
acid with potassium. 

The easiest method of obtaining it is to decompose boro- 
-fluoride of potassium by means of potassium and heat, 

Properties. A dark olive-colored solid, without taste or 
odor; a non-conductor of electricity ; sp. gr. nearly 2 ; insolu- 
ble in water, alcohol, ether, and oils ; does not decompose 
water at any temperature, and may be subjected to intense 
heat in close vessels without change ; heated to 600° in the 
■ir, it ignites, and is converted into boracic acid. When 



216 Boron and Oxygen 

heated with nitric acid, or with any substance which yields 
cxygen freely, it passes into boracic acid. 

Boron and Oxygen. 

Boracic Acid. Symb. B + 30. Equiv. 34.9. Sp. gr. 
1.479, water 1. This substance exists in nature in small 
quantities in the Lipari Islands, and the hot springs of Lasso, 
in the Florentine territory ; in combination with soda, in 
the well-known substance borax, the biborate of soda, used 
by smiths as a flux. It is also a constituent of the minerals 
boracite and datholite. 

Process. To a solution of purified borax in boiling water ) 
add half its weight of sulphuric acid, diluted with an equal 
quantity of water. On evaporation* and cooling, shining 
crystals of boracic acid will be deposited ; ; t may be purified 
by repeated solution in hot water and crystallization. This 
is a hydrate, containing 1 eq. of acid and 3 of water. The 
anhydrous acid may be obtained by heating this in a plati- 
num crucible. 

Properties. The hydrous acid exists in the form of thin 
white scales, without odor, and nearly tasteless, sparingly 
soluble in water, which reddens vegetable blue colors, and, 
like the alkalies, turns turmeric paper brown, soluble in boil- 
\ng alcohol, and gives a beautiful green color to flame. 

The anhydrous acid is a hard, colorless, transparent glass, 
absorbs water rapidly from the air, and should be kept in 
well-stopped vials ; exceedingly fusible, and communicates 
\uis property to the substances with which it unites. Hence 
its use in the arts as &flux. 



* Fig. 94 represents the form of evaporating 
dishes ; some are made of clay and sand, oth- 
ers of porcelain, glass, silver, platinum, and 
gold. The substance to be evaporated is 
poured into them, and they are placed in a 
sand bath, which is simply a quantity of com- 
mon sand contained in an iron vessel, and 
connected generally with the furnace or fire- 
place, so as to be kept constantly at a tem- 
perature below the boiling point. 



Fig. 94. 




Selenium. 217 



Boron and Chlorine. 

Terchloride of Boron. Symb. B + 3C1. Eq. 117.16. Pro- 
duced by the spontaneous combustion of boron in chlorine 
gas. It is rapidly absorbed by water, and unites with am- 
monia, forming a volatile fluid. It is also formed, according 
to Despretz, by passing dry chlorine gas over charcoal and 
boracic acid, ignited in a porcelain tube. It was first 
noticed by Davy, and examined by Berzelius, Dumas, and 
Despretz. 

Boron and Fluorine. 

Fluoboric Acid. Symb. B + 3F. Equiv. 66.94. Sp. gr. 
2.3622. Discovered by Gay Lussac and Thenard, in 1810. 

Process. Mix 1 part of pure boracic acid and 2 of fluor- 
spar with 12 of sulphuric acid, in a glass flask, and apply heat ; 
or heat a strong solution of hydrofluoric and boracic acids in 
a metallic retort. 

Properties. A colorless gas, of a penetrating, pungent 
odor ; extinguishes flame, reddens litmus powerfully, and 
unites with bases forming salts called jluoborates. 

It has a powerful affinity for water, which absorbs 700 
volumes of the gas ; becomes hot, fuming, and caustic ; 
attacks animal and vegetable substances with great energy. 
Some doubt yet exists concerning its true natiu e. 

Boron and Sulphur. 

Sulphur et of Boron is formed, according to Berzelius, by 
burning boron in the vapor of sulphur. The product is a 
white, opaque mass, readily decomposed by water. 



Sect. 12. Selenium. 
Symb. Se. Equiv. 39.6. Sp. gr. 4.32. 

Selenium was discovered by Berzelius, in 1818, and 
named Selenium, from Selene, the moon, because he at first 
mistook it for tellurium. 

Natural Histonj. It is found in small quantities among 
10 



218 Selenium. 

the volcanic products of the Lipari Islands, in Clausthal in 
the Hartz, combined with lead, cobalt, silver, mercury, and 
copper. Berzelius obtained it from the iron pyrites of 
Fahlun. 

Process. Mix the native sulphuret of selenium with 8 
times its weight of peroxide of manganese, and expose it to a 
low red heat in a glass retort, the beak of which dips into 
water. The manganese yields its oxygen to the sulphur, 
and the selenium sublimes pure, or in the form of seleniou3 
acid. 

Properties. A brittle, opaque solid, without taste or odor ; 
its lustre is metallic, resembling lead in the mass, but the 
powder has a deep red color ; softens at 212°, and may be 
drawn out into fine, transparent threads, which appear red by 
transmitted light ; becomes fluid a little above 212°, and boils 
at 650°, yielding an inodorous vapor of a deep yellow color ; 
sublimes, in close vessels, without change, and condenses 
into dark globules, or into a cinnabar-red powder, if the ves« 
sels are large. Heated in the open air, or in oxygen, it com- 
bines with the oxygen ; under the blowpipe, it emits the 
strong odor of horseradish. 

Selenium and Oxygen. 

Oxide of Selenium (Symb. Se-j-O. Equiv. 47.6) is 
formed by heating selenium in a limited quantity of air, and 
washing the product to clear it from selenious acid. It is a 
colorless gas, which gives the peculiar odor to the selenium, 
when burned in the wick of a lamp. 

Selenious Acid (Symb. Se-}-20. Equiv. 55.6) is formed 
by dissolving selenium in nitrohydrochloric acid. On evap- 
oration, the acid is left as a white, crystalline solid, of a pour 
and burning taste; dissolves readily in water and alconol, 
and attracts moisture from the air. It has distinct acid 
properties, and its salts are called selenites. It is decom- 
posed by all substances which have a strong attraction foi 
oxygen. 



Compounds of Selenium. 219 

Selenic Acid (Symb. Se-|-30. Equiv. 63.6) was first 
noticed by M. Nitzsch, and described by Mitscherlich in 

1827. 

Process. It is obtained by fusing nitrate of potassa or 
soda with selenium ; a metallic seleniuret with selenious acid, 
or any of its salts. (For process, see Turner, 6th ed. p. 209.) 

Properties. A colorless liquid : sp. gr. at 329°, 2.524 ; at 
512°, 2.60. It is decomposed by heat at 536°, and is resolved 
into oxygen and selenious acid ; has a powerful affinity for 
water, with which it combines, with the evolution of as much 
caloric as sulphuric acid and water. It dissolves zinc, iron, 
copper, and gold; unites with bases, and forms salts analo- 
gous, in composition and form, to those of sulphuric acid. 

Chloride of Selenium is a white solid, obtained by placing 
selenium in chlorine gas. 

Bromide of Selenium is an orange-colored solid ; soluble 
in water, and obtained by dropping selenium into bromine. 
The combination is violent, with the evolution of much heat. 

Selenium and Hydrogen. 

Hydroselenic Acid. Symb. Se-(-H. Eq. 41. This acid 
was discovered by Berzelius, and some doubt exists as to its 
composition. 

Process. It may be obtained by the action of hydrochloric acid upon 
a concentrated solution of any hydroseleniate. 

Properties. A colorless gas, with an odor resembling hy- 
drosulphuric acid. It irritates the membrane of the nose, 
exciting catarrhal symptoms, and produces temporary insen 
sibility. Water absorbs it readily, and the solution reddens 
litmus, and leaves a brown stain upon the skin. On exposure 
to the air, it is decomposed, but decomposes all the salts of 
the common metals, forming seleniurcts of the metal. 

Selenium and Sulphur. 

Bisidphuret of Selenium (Symb. Se-f-2S. Eq. 718) was 
ebtained by Berzelius, by adding hydrosulphuric acid to a 
solution of selenious acid, when it is precipitated as an 
orange-colored powder ; fuses at 212°, sublimes at a high 



220 Silicon. 

temperature without change ; when heated in the open air, i 
inflames, and is decomposed by nitrohydrOchloric acid. 

Seleniuret of Phosphorus, or Phosphuret of Selenium, is 
prepared in the same manner as the sulphuret of phosphorus. 
It is a very fusible substance ; imfammable, and decomposes 
water slowly, yielding seleniuret of hydrogen, and one of the 
acids of phosphorus. 



Sect. 18. Silicon. 

Symbol, Si. Equivalent, 22.5. 

Silicon was obtained by Berzelius, in 1824, by the action of 
potassium on fluosilicic acid gas. It was at first called sili- 
cium, and regarded as a metal, but it is destitute of the me- 
tallic properties. 

Properties. Silicon is a solid, of a dark brown color, and 
a non-conductor of electricity. 

Before ignition it is not oxidized, or dissolved by hot sul- 
phuric or nitrohydrochloric acids, but is soluble in hydro- 
fluoric acid, and in a hot, concentrated solution of caustic 
potassa. It burns readily in air, and vividly in oxygen gas ; 
but after ignition, it is insoluble and non-combustible. It is 
oxidized by heating it with nitrate of potassa, and explodes 
when dropped upon fused hydrate of potassa, soda, or baryta, 
in consequence of the evolution of hydrogen. 

Silicon and Oxygen. 

Silicic Acid, Silica. Symb. Si + 30. Equiv. 22.5 -f 
24=: 46.5. 

Natural History. Silicic acid, also called silica, siliceous 
earth, and silex, constitutes nearly 40 per cent, of the crust 
of the globe. Hence it is the principal ingredient of exten- 
sive mountain masses, of sand, and of several minerals, such 
as quartz, flint, chalcedony, rock-crystal, etc. It is the most 
abundant ingredient in nearly all soils. 

Process. It may be prepared by heating rock-crystals., and 
throwing them, red-hot, into cold water. 



Compounds of Silicon. 221 

• 

Properties. When reduced to powder, it is white, insipid, 
and inodorous. It is very infusible, requiring the heat of the 
compound blowpipe to fuse it; insoluble in water, unless 
presented in the nascent state ; does not act upon test paper, 
but in every other respect, has the properties of an acid. Its 
combination with the fixed alkalies is effected by mixing 
pure sand with carbonate of potassa. If 3 parts of the car- 
bonate to 1 of sand are mingled, the fused silicate is solu- 
ble in water ; but if 1 part of the carbonate to 3 of sand 
be employed and fused, the well-known substance glass is 
formed, which is transparent, brittle, insoluble in water, and 
affected by no acid except the hydrofluoric. 

Every kind of common glass is a silicate, and the different 
varieties are due to the proportions of the constituents, to the 
nature of the alkali, or the presence of foreign matter. Thus 
green bottle glass is made of materials containing iron ; 
Crown glass, of pure alkali and sand, free from iron. Plate 
glass, for mirrors, is made of the purest materials. Flint glass 
contains red lead ; and sometimes peroxide of manganese, 
or nitre, is added to oxidize the carbon contained in the 
materials. 

Chloride of Silicon (Symb. Si + Cl. Equiv. 57.92) is 
prepared by burning silicon in chlorine gas. The product is 
a limpid, volatile liquid, flying off in white vapor when ex- 
posed to the air, with a suffocating odor resembling cyano- 
gen ; boils at 124° Fahr. 

Bromide of Silicon (Symb. Si -f- Br. Equiv. 100.6) was obtained by 
Serullas, in the same manner as the chloride. It is a very dense, color- 
less liquid, emitting dense fumes. 

Sulphuret of Silicon (Symb. Si -j-S. Equiv. 38.6) is formed by heat- 
ing silicon in the vapor of sulphur. It is a white, earthy substance, 
instantly converted by the action of water into hydrosulphuric and 
silicic acids. 

Fluosilicic Acid, (Symb. Si-f-F. Equiv. 41.18) is formed by bring- 
ing hydrofluoric and silicic acids into contact. It is a colorless gas, 
which extinguishes flame, destroys animals immersed in it, and acta 
powerfully upon the respiratory organs. Water acts upon this gat 
with some change of properties, and the solution is*' called silicohy' 
irojluoric acid. 






222 Metals, with their Binary Compounds. 

CHAPTER II. 

Class II. Metals, with their binary Compounds. 

General Properties of Metals. 

Metals are the most important of substances. They are 
distinguished from other substances by the following prop- 
erties : — 

1. They are all conductors of electricity and of caloric. 

2. When combined with oxygen, chlorine, iodine, sulphur, 
and similar substances, and subjected to the voltaic battery, 
they always go to the negative electrode or pole, and hence 
are called positive electrics. 

3. Metals are opaque ; that is, they do not permit the light 
to pass through them, although reduced to thin leaves. 

4. They are good reflectors of light, and possess a peculiar 
lustre, which is termed the metallic lustre. Any substance 
which has the above properties, may be regarded as a metal. 

Metals differ greatly in their Properties. 

1. In their specific gravity. Most of the metals are re- 
markable for their weight, such as gold and platinum, which 
are more than nineteen times as heavy as an equal bulk of 
water ; while some, potassium and sodium, are lighter than 
water. 

2. In their malleability, or the property of being beaten 
into thin leaves by hammering. Gold, silver, copper, tin, 
platinum, palladium, cadmium, lead, zinc, iron, nickel, po- 
tassium, sodium, and frozen mercury, are malleable. The 
others are mafleable only in a slight degree, or, like arsenic, 
antimony, and bismuth, brittle. Gold is the most malleable 
of metals; one grain of which may be extended so as to 
cover fifty-two square inches of surface, and to have a thick- 
ness not exceeding sW^su °^ an mcn - 



General Properties of Metals. 223 

3 In their ductility, or the property of being drawn out 
mto wires. Most of the malleable metals are also ductile. 
Gold, silver, platinum, iron, and copper, are the most ductile. 
Gold wire may be obtained so fine that it shall not exceed 
■f<jW of an inch in diameter, and platinum ■g-^^tr °f an 
inch. The tenacity of a metal is measured by the weight 
which a wire of a certain diameter can support without 
parting. 

4. In hardness. Titanium, manganese, iron, nickel, cop- 
per, zinc, and palladium, are hard metals. Gold, silver, and 
platinum, are softer than these, lead still softer, and po- 
tassium and sodium yield readily to the pressure of the 
fingers. 

5. In their structure. Many have a crystalline structure. 
Iron is fibrous; zinc, bismuth, and antimony, are lamellated; 
gold, silver, and copper, are found naturally in crystals, and 
others may be made to assume the form of crystals, when 
they pass gradually from a liquid to a solid state. Most of 
them, in crystallizing, assume the figure of a cube, the reg- 
ular octohedron, or some form allied to it. 

6. In their fusibility. All are solid, at the common tem- 
perature of the atmosphere, except mercury, which is solid 
at -40° Fahr. Mercury, potassium, sodium, cadmium, tin, 
bismuth, lead, tellurium, antimony, and probably arsenic, are 
fusible below red heat. The rest require a higher tempera- 
ture to fuse them ; and some of these, such as platinum, ceri- 
um, rhodium, and columbium, require the heat of the com- 
pound blowpipe to render them liquid. 

7. In volatility. Cadmium, mercury, arsenic, tellurium, 
potassium, sodium, and zinc, are volatilized by heat. Most 
of the others may be exposed to the most intense heat of a 
smith's forge, without being converted into vapor. 

8. In their affinity for the other simple substances. Metals 
generally have an extensive range of affinity; hence they 
are rarely found in the earth in their simple or pure state, but 
are generally combined with other bodies, especially with 



224 Metals. — General Properties. 

oxygen and sulphur, in which state they are said to bs 
mineralized. 

It is a remarkable fact, that they are not disposed to com 
bine with compound bodies They combine with each-other, 
and with other simple substances, generally in a few definite 
proportions. 

They all combine with oxygen, though with different de- 
grees of energy. Iron and copper are slowly oxidized at 
common temperatures, while gold will sustain the most in- 
tense heat of furnaces without oxidation. Potassium and 
sodium will even decompose water, to obtain the oxygen, the 
moment they come in contact with it. In all these cases 
they produce the phenomena of combustion. Hence they 
are said to be combustible. With chlorine, iodine, bronime, 
etc., they combine with more or less energy, giving rise 
to the same phenomena. Some unite with oxygen in one 
proportion only, but most have two or three degrees of 
oxidation. The protoxides form the strong alkaline bases, 
combining with acids to form neutral salts. They are gene 
rally the only salifiable bases. 

The binoxides and peroxides, with a few exceptions, are 
either neutral or acid in their properties ; the acids generally 
contain the largest amount of oxygen. 

When metals unite with chlorine, iodine, bromine, sulphur, 
&c, the compounds they form are similar in composition to 
the oxides of the same metals, so that if we know the com- 
position of the one, we can infer that of the other : thus the 
two oxides of iron unite in the proportions of FeO and Fe 2 3 ; 
the sulphurets and chlorides of iron have a similar com- 
position, FeS, Fe 2 S 3 — -FeCl, and Fe 2 CP. To this rule there 
are a few exceptions. Sulphur sometimes forms a greater 
number of compounds with a metal than oxygen ; in which 
case there can be no corresponding oxides. This is the case 
with iron, arsenic, potassium, and a few others. The chlo- 
rides of any metal generally correspond in number with it* 
oxides, never greater and in but few cases less in number. 



Metals. — General Properties. 225 

Among the non-metallic bodies, hydrogen alone forms an 
oxide, (water.) which is capable of* uniting with acids, and in 
this respect it bears a striking analogy to the metals. Hy- 
drogen has been regarded as a metal in the gaseous state. 

Many metals form acids with oxygen, as well as oxides ; 
only three, arsenic, antimony, and tellurium, are incapable 
of forming protoxides, but are distinguished for forming strong 
oxygen acids. 

Oxides sometimes combine with each other, and form defi- 
nite compounds. The action of the metals upon the simple 
non-metallic substances will be noticed in their proper place. 

Metallic oxides may be reduced to the metallic state by 
heat, by the united agency of heat and combustible matter, 
by voltaic electricity, and by the action of the deoxidizing 
agents on metallic solutions. 

When the hydracids, such as hydrochloric, hydrobromic, 
hydriodic, and hydrofluoric acids are poured upon the metals, 
their action is different from that of oxygen acids. In the 
latter case, the metal becomes oxidized, and the acid unites 
to form a ternary compound, or salt ; but in the former case, 
the acid is decomposed, its hydrogen escapes, and the chlo- 
rine, bromine, iodine, and fluorine combine directly with the 
metal, forming a binary compound. Thus hydrochloric acid 
poured on zinc, will form chloride of zinc, ZnCl, or on so- 
dium will form chloride of sodium, (common salt.) 

It should be observed here, that most chemists place such 
compounds among the salts, dividing the latter into two 
classes ; thus extending Ihe definition of a salt so as to in- 
clude such compounds (see page 298), The reason for such 
a classification is, that though they resemble oxides in com- 
position, they are more nearly allied to salts, in their proper- 
ties. Thus common salt, the substance from which we 
derive the name of salts, is a chloride of sodium, a binary 
compound, but in its properties it resembles the ternary com- 
pounds or oxygen salts. 
10* 



226 Metals. — General Properties. 

It was formerly supposed that when common salt and other 
compounds having a similar constitution, sometimes called 
haloid salts, — that is, after the form of sea-salt, — were dis- 
solved in water, they formed a compound precisely similar 
to an oxygen salt. For example, when common salt was 
dissolved in water, it was supposed that the oxygen of the 
water united with the sodium, forming an oxide, and its hy- 
drogen united with the chlorine, and formed hydrochloric 
acid, these combined and formed hydrochlorate of soda. But 
no such compound exists. 

The water is not decomposed, and hence the hydracids da 
not form any compounds similar to the oxygen acids, unless it 
be in the case of their action on ammonia, which more prop, 
erly belongs to the subject of organic chemistry. The true 
explanation of the action of the hydracids on the metallic ox- 
ides has been given above. But perhaps the changes which 
take place may be more clearly exhibited by means of a dia- 
gram ; thus, take hydrochloric acid and soda. 

Hydrochloric { Chlorine ^^_ ^^^-^ Water, 
acid \ Hydrogen 




( Sodium — ^- ^ "-Chloride of 

Soaa \ f. ^^ ,. 

I Oxygen"^ sodium. 

Thus it appears that the action of a hydrogen acid on a 
metallic oxide results in the formation of a binary compound, 
one of which is water and the other is an ide of the metalj 
similar in constitution to the oxides and the sulphurets. 

If therefore we class the chlorides, iodides, &c, of the 
metals with the oxygen salts, the reason for it cannot be found 
in their constitution, but simply because they agree in physi- 
cal properties with true salts ; we have therefore concluded to 
retain them among the ides of the metals. 

The number of metals is generally reckoned at 42, to 
which three or four have lately been added, but are of very 
rare occurrence. Most of the metals are known only t3 
chemists. Many of them have scarcely been examined, ex- 
cept by those who discovered them. The following table 
contains their names, with the date at which they were dis. 
covered, and the names of the chemists by whom the die 
covery was made :— 



Tabic of the Discover y of Metals. 



227 



Names of Metals. | Authors of the Discovery. 



Gold 

Silver 

Iron 

Copper 

Mercury 

Lead 

Tin . . 

Antimony . 

Bismuth 

Zinc 

Arsenic 

Cobalt 

Platinum 

Nickel 

Manganese 

Tungsten . 

Tellurium . 

Molybdenum 

Uranium 

Titanium 

Chromium 

Colurnbium 

Palladium 

Rhodium 

Iridium 

Osmium 

Cerium 

Potassium 

Sodium 

Barium 

Strontium 

Calcium 

Cadmium 

Lithium 

Zirconium 

Alummium 

Glucinium 

Yttrium 

Thorium 

Magnesium 

Vanadium 

Latanium 



Known to the Ancients. 



Described by Basil Valentine . 

Described by Agricola 

First mentioned by Paracelsus 

Brandt . . 

Wood, assay-master, Jamaica 
Cronstedt ..... 
Gahn and Scheele . 
D'Elhuyart .... 

Mailer 

Hielm ..... 
Klaproth ..... 

Gregor 

Vauquelin .... 

Hatchett ... 

Wollaston .... 

Descotils and Smithson Tennant 
Smithson Tennant . . 
Hisinarer and Berzelius . 



Dates of the 
Discovery, 



Davy 



Stromeyer 
Arfwedson 
Berzelius 

Wbhler . 

Berzelius . 
Bussy 
Sefstrdm 
Mosander 



1490. 

1530- 

16th century. 

1733. 

1741. 
1751. 
1774. 
1781. 

1782. 
1782. 
1789. 
1791. 
797. 
1802. 

1803, 

1803 
1803. 
1804. 



1807. 



1818. 
1818. 
1824. 

1828. 

1829. 
1829. 
1830. 
1839. 



It will be found convenient, in studying the properties of 
the metals, to arrange them in groups. They may be divided, 
for this purpose, into the two following orders : — 

Order I. Metals which, by oxidation, yield alkalies or earths 
Order II. Metals, the oxides of which are neither alka- 
*m nor earths. 



228 Metals. — Potassium. 

Order I. includes twelve metals, which may be arranged 
in three sections or divisions : — 

Section 1. Metallic bases of the alkalies. These are, 

Potassium, Sodium, Lithium. 

Section 2. Metallic bases of the alkaline earths. These 

are, 

Barium, Strontium, Calcium, Magnesium. 

Section 3. Metallic bases of the earths. These are, 

Aluminium, Yttrium, Zirconium. 

Glucinium, Thorium, 

Order II. The metals belonging to this order are ar 
ranged in the three following sections : — 

Section 1. Metals which decompose water at a red heat * --- 

Manganese, Cadmium, Cobalt, 

Iron, Tin, Nickel. 

Zinc, 

Section 2. Metals which do not decompose water at any 

temperature, and the oxides of which are not reduced to the 

metallic state by the sole action of heat : — 

Arsenic, Columbium, Titanium, 

Chromium, Antimony, Tellurium, 

Vanadium, Uranium, Copper, 

Molybdenum, Cerium, JLead. 

Tungsten, Bismuth, 

Section 3. Metals, the oxides of which are decomposed by 

a red heat : — 

Mercury, Platinum, Osmium, 

Silver, Palladium, Iridium. 

Gold, Rhodium, T. 



Sect. 1. Metallic Bases of the Alkalies. 
POTASSIUM. Symb. K. Equiv. 39.15. Sp. gr. 0.865. 

History. The discovery of potassium, or Jcalium. as it 
was at first called, was made by Davy, in 1807, and consti- 
tutes an era in the history of chemical philosophy, as it led 



Properties of Potassium. 229 

to the discovery of the metallic bases of the other alkalies 
and alkaline earths, and to the decomposition of a variety of 
compounds which were before regarded as simple bodies. 

The discovery was made by subjecting the hydrate of 
potassa to the influence of a powerful galvanic battery of 
200 pair of plates ; oxygen appeared at the positive, and a 
small globule of a metallic lustre at the negative pole, which 
proved to be the metal potassium. 

Process. Potassium is obtained in small quantities by 
galvanism ; but the best method is that of M. Curaudau, 
which was improved by Brunner, and modified by YVohler. 
The substance employed is carbonate of potassa, prepared 
by heating cream of tartar to redness in a covered crucible. 
This is raised to a high temperature, in connection with 
charcoal, in an iron retort ; the oxygen of the potassa com- 
bines with the carbon, and the potassium distils over. 

Properties. Potassium, at common temperatures, is a 
soft, malleable solid, yielding to the pressure of the fingers, 
like wax ; of a decidedly metallic lustre ; similar to mercury 
in color ; somewhat fluid at 70°, and perfectly liquid at 150° ; 
cooled to 32°, it is brittle ; sublimes at a low red heat in 
close vessels secluded from the air ; a good conductor of 
electricity and of caloric. 

But its most remarkable property is its affinity for oxygen. 
It oxidizes rapidly in the air or oxygen gas ; but if a piece be 
thrown upon water, it will decompose it rapidly, disengaging 
so much heat that the potassium takes fire, and burns with a 
beautiful purple fame. The evolution of hydrogen gas 
causes it to move about upon the surface of the water, and, 
combining with the potassium, augments the brilliancy of 
the combustion. 

Exp. Invert a wine-glass filled with water in the cistern, and in- 
troduce a small piece of potassium ; it will rapidly decompose the 
water, and the escape of hydrogen gas will displace the water in tho 
glass. This gas may then be ignited. 

Exp. Heat a small piece of iron, and drop upon it potassium; then 
invert over it a jar of oxygen gas. 

Exp. Drop a piece upon ice, and it will instantly inflame ; a deep 
hole is made in the ice, containing pure potassa with water. 

Exp. To show that the action of potassium upon water produces an 



^30 Metals. — Compounds of Potassium. 

alkali, drop a small piece into a bottle containing vegetable infusion 
and it will instantly turn it green. In consequence of its affinity fo? 
oxygen, it must be kept under naphtha, or the essential oil of copaiba. 

Remark. In the description of the metallic compounds, 
the abbreviations symh. and equiv. will be omitted, and the 
symbols and equivalents placed immediately after the names 
of the substances. 

Compounds of Potassium. 

Protoxide of Potassium, (K-j-O. 47.15,) commonly called 
potash, or potassa, is always formed when potassium is put 
into water, or burned in oxygen gas. It exists in nature in 
the minerals, feldspar, mica, and several others ; in all vege- 
tables, from which it is obtained by leaching their ashes, and 
boiling the lye. 

Properties. The pure potassa is a white solid, very caus- 
tic, possessing powerful alkaline properties ; easily fused by 
heat, but not decomposed ; deliquesces in the air, and hence 
is very soluble in water, forming with it a hydrate, which 
retains the water under the most intense heat. 

The Hydrate of Potassa contains 1 eq. of water, and is 
similar in its properties to the anhydrous potassa. The 
aqueous solution of the hydrate, called aqua potassa, may 
be prepared by decomposing the carbonate with lime. 

Exp. Put quick lime, with half its weight of carbonate of potassa 
dissolved in 8 or JO times its weight of water, into a clean iron vessel, 
and put it into well-stopped bottles, to exclude the air, from which it 
will absorb carbonic acid. If the solution is pure, it will not effervesce 
with acids. 

The solid hydrate may be made from this by evaporation, and further 
purification by alcohol, which dissolves only the pure hydrate ; the 
alcohol is then driven off by heat. This was formerly called lapis 
causticus, but the colleges of Edinburgh and London called it potassa 
fusa. 

Tests. Potassa may be distinguished from all other sub- 
stances by the precipitates thrown down from its salts in 
solution. 

Exp. 1. Take any of the salts of potassa in solution, and pour into 
them tartaric acid ; a white precipitate will be thrown down — the bi- 
tartrate of potassa , 



Compounds of Potassium. 231 

Exp. 2. Chloride of platinum will give a yellow, and when dissolved 
in alcohol, a pale yellow, precipitate. 

Exp. 3. Alcoholic solution of carbazotic acid throws down yellow 
crystals of carbazotate of potassa. This is the most delicate test. 

Uses. Potassa, being a very powerful alkali, is of great 
use in chemistry and the arts. It forms the bases of most 
soaps; the crude potash is employed for making glass. 

Owing to its affinity for carbonic acid, it is used for ab- 
stracting that substance from gaseous mixtures, and for 
depriving them of moisture. 

Teroxide of Potassium (K-|-30. 63.15) is formed when 
potassium is burned in the air or oxygen gas. It is an 
orange-colored substance, caustic, alkaline, heavier than 
potassium, and decomposed by galvanism and by water ; by 
the latter it is resolved into the protoxide and oxygen ; fuses 
below a red heat, in which state it burns vividly, in contact 
with combustibles. 

Chloride of Potassium (K -\- CI. 74.57) was long known by the 
names ' febrifuge salt of Sylvius,' ' regenerated sea-salt.' 

It may be formed by the spontaneous combustion of potassium in 
chlorine, or by dissolving potassium in hydrochloric acid, and evapo- 
rating the solution slowly to dryness. 

Properties. It occurs in cubic crystals, colorless, of a 

saline and bitter taste, insoluble in alcohol, and soluble in 3 

parts of water at 60°, and in less at 212° Fahr. 

Iodide of Potassium (K-f-L 165.45) is formed by heating potassium 
with iodine, or by heating the iodate of potassa. 

Properties. Fuses readily, and is converted into vapor 
below a red heat ; deliquesces in air ; very soluble in water ; 
dissolves in strong alcohol, and, by evaporating the solution, 
yields colorless cubic crystals of iodide of potassium. 

Bromide of Potassium, (K-}-Br. 117.55,) formed by a 

process similar to that for the iodide, (using bromine instead 

of iodine,) and has similar properties; very soluble in water, 

which, by evaporation, yields anhydrous cubic crystals; 

easily fused, and decrepitates, like sea-salt, when heated. 

Exp. Put a small piece of potassium into a wine-glass containing a 
few drops of bromine ; the two bodies will combine with explosive 
violence. 

FluoHde of Potassium (K + F. 57.83) is formed by nc 



232 Metals. — Compounds of Potassium 

merely saturating hydrofluoric acid with carbonate of potassa 
evaporating to dryness, and igniting to expel excess of acid. 

Properties. It has a sharp, saline taste, alkaline to the 
test papers, soluble in water, and the solution acts on glass 
It is obtained from its solution, by evaporation at 100°, ir, 
cubes or rectangular four-sided prisms } very deliquescent. 

Hydruret of Potassium. Discovered by Gay Lussac and 
Thenard, and may be formed by heating potassium in hydro- 
gen gas. It is a gray solid, readily decomposed by heat or 
water. Gaseous hyduret of potassium is produced when 
hydrate of potassa is decomposed by iron, at a white heat. 
It is a colorless gas, and burns spontaneously in air or oxy- 
gen gas, but loses its inflammability by standing over mercury. 

Nituret of Potassium consists, according to Thenard, of 100 parts of 
potassium to 11.723 of nitrogen, and is formed by heating potassium 
with ammoniacal gas. 

Sulphurets of Potassium. These are five in number, de- 
pendent on the quantity of sulphur. 

The Protosulphuret of Potassium (K -j- S. 55.25) is prepared by 
burning potassium and sulphur in the air, or by decomposing the sul- 
phate of potassa by charcoal or hydrogen gas at a red heat. Mixed 
with powdered charcoal, it kindles spontaneously. 

The Bisulphuret of Potassium (K-J-2S. 71.35) is formed by ex- 
posing a saturated alcoholic solution of hydrosulphate of sulphuret of 
potassium, until a pellicle begins to form, and then evaporating to 
dryness. 

The Tersulphuret of Potassium, (K-J-3S. 87.45) is formed by heating 
carbonate of potassa to low redness, with half its weight of sulphur, 
known by the name of liver of sulphur. 

The Quadrosulphuret of Potassium (K-4-4S. 103.55) is prepared ')y 
transmitting the vapor of bisulphuret of carbon over sulphate of potassa 
at a red heat, until carbonic acid gas ceases to be disengaged. 

The Quinto sulphuret of Potassium (K-J-5S. 119.65) is formed by 
fusing carbonate of potassa with its own weight of sulphur. 

The properties of the four last compounds are similar ; 
they are deliquescent, have a sulphureous odor, and are 
soluble in water. A solution of the last dissolves sulphur, 
and renders it probable that other compounds may be 
formed. 

Pliosphurets of Potassium. Several compounds exist, bu| 
their, composition is unknown. Obtained by burning potas* 
sium in phosphuret of hydrogen. 

Seleniuret of Potassium. Formed by fusing potassium and 
selenium together. They combine with explosive violence ; 



Sodium. 233 

and a crystalline, fusible compound results, of an iron-gray 
color, and metallic lustre. 

Cyanide of potassium (K-f-Cy. 65.54) is formed by heating to red 
ness the anhydrous ferrocyanide of potassium in an iron bottle. 

Properties. Easily fused, and crystallizes in colorless 
cubes : pungent and alkaline to the taste, and poisonous, act- 
ing like the hydrocyanic acid ; deliquescent, and very solu- 
ble in water ; used sometimes as a medicine. 

Sulphocyanide of Potassium K -j- CyS 2 . 97.74. 



SODIUM. Symb. Na. Equiv. 23.3. Sp. gr. 0.972. 

Sodium was discovered by Sir H. Davy, in 1807, a few 
days after the discovery of potassium, and by a similar 
process. 

Process. It may be obtained in small quantities by gal- 
vanism. But the process of obtaining it from soda, now 
generally practised, is precisely the same as that for potas- 
sium. 

Properties. Sodium resembles potassium in many of its 
properties. It is a white, opaque solid, of a metallic lustre, 
resembling silver ; yields readily to the pressure of the 
fingers, and may be formed readily into leaves ; fuses at 200° 
Fahr., and is vaporized at a red heat. 

Sodium has so strong a% affinity for oxygen that it rapidly 
decomposes water to obtain it, but does not inflame unless 
the water is heated, in which case it throws out beautiful 
scintillations, often with violent combustion. 

Exp. Thrown upon water, it moves about upon its surface, having 
the appearance of a silver ball, gradually growing less till the wnola 
disappears. 

Exp. Drop a piece of sodium into a test-tube partly filled with warrr. 
water; it will soon burst into a flame, and often explode with violence. 

It oxidizes in the air or oxygen gas, but not so rapidly as 

po assium ; hence, like that metal, it must be kept under 

naphtha, The product of its combustion in oxygen, and its 

action upon water, is soda, the alkaline properties of which 

may be tested by dropping a small piece of the metal into a 

bottle containing a vegetable infusion. 



234 Metals. — Compounds of Sodium 

Compounds of Sodium. 

Protoxide of Sodium, (NaO. 31.3,) commonly called soda 
and by the Germans natron, is formed by the oxidation of 
sodium in air or water. 

Properties. A gray solid, similar to potassa, which it 
resembles in most of its properties ; very caustic, and has 
powerful alkaline properties. 

The hydrate has 1 eq. of water, and is easily fused. In 
other respects, it is similar to the anhydrous soda ; absorbs 
carbonic acid from the air, and passes into carbonate. 

It is distinguished from other alkaline bases by yielding, 
with sulphuric acid, the well-known substance called Glau 
ber's salts. All its salts are soluble in water, and are not 
precipitated by any re-agent, and give a rich color to the 
blowpipe flame. The soda of commerce is generally a car- 
bonate prepared from the ashes of marine plants, in the 
same manner as potash is from land plants. 

Uses. Employed for the manufacture of hard soaps, and 
for culinary and medical purposes. 

Sesquioxide of Sodium (2Na -j- 30. 70.6) is formed when 
sodium is heated to redness, in excess of oxygen gas. It has 
an orange color, but no acid or alkaline properties. It is 
resolved by water into soda and oxygen. 

Chloride of Sodium. Na-f-Cl. 58.72. This substance is 
formed by burning sodium in chlorine gas, or by saturating 
soda with hydrochloric acid, and evaporating to dryness. It 
is a very abundant natural product, under the name of rock 
salt. It exists in sea-water and salt-springs, from which it 
is obtained by evaporation. Great quantities are manufac- 
tured on the sea-coast of New England, and at Salina, N. Y. 
The water at the latter place, according to the analysis of 
Beck, contains one seventh of its weight of pure dry chloiide 
of sodium. 

Properties. A well-known solid, crystallizing in regular 
cubes, and by sudden evaporation, in hollow, quadrangular 
pyramids. It is dissolved in 2J times its weight of water, a? 



Compounds of Sodium. 235 

60° Fahr. ; gradually fuses when heated, and decrepitates 
when thrown into the fire ; is decomposed by carbonate of 
pota&sa and nitric acid. The different kinds of salt, such as 
stored, fishery, bay, &,c., arise from its different forms, and 
not from a difference of chemical constitution. It contains 
small quantities of sulphate of magnesia and lime, and chlo- 
ride of magnesium. 

Uses. The utility of salt depends on its property of pre- 
serving animal and vegetable substances from putrescence. 

Iodide of Sodium, (Na-j-I. 149.6,) prepared in the same manner 
as the iodide of potassium, exists in sea-water, salt-springs, and in the 
residual liquor from kelp. 

Bromide of Sodium, (Na-f-Br. 101.7,) analogous to sea-salt, exists 
in sea-water and salt-springs, and crystallizes in cubes. 

Fluoride of Sodium (Na-|-F. 41.98) is formed by neutralizing hydro- 
fluoric acid with soda ; crystallizes in cubes, and when carbonate of 
soda is present, in octohedrons. Nearly insoluble in alcohol ; soluble in 
twenty-five times its weight of water ; attacks glass vessels when 
evaporated in them — a property which is common to most of the com- 
pounds of fluorine. 

Sulphuret of Sodium (Na-f-S. 39.4) is obtained in the same manner 
as the protosulphuret of potassa, and has similar properties. 

The Cyanide of Sodium (Na-f-Cy. 49.69) and the Sulphocyanide 
of Sodium (Na-j-CyS 2 . 81.89) are similar to the corresponding com- 
pounds of potassium. 

Chloride of Soda is prepared by passing a current of chlo- 
rine gas into a cold solution of caustic soda. This liquor 
has received the name of Labarraque's Disinfecting Soda 
Liquid, and is used extensively in the arts, and in med- 



Propcrties. A liquid of a pale yellow color, with slight 
odor of chlorine. Its taste is sharp, saline, and but little 
alkaline; reddens turmeric, and then bleaches it. When 
evaporated, it yields damp crystals ; decomposed by exposure 
to the air. 

Uses. It may be used for all the purposes of bleaching tc 
which chlorine was formerly applied, in medicine to purify 
apartments, dissecting-rooms, for destroying the fetor of 
ulcers, and for removing the offensive odors of sewers, drains, 
and all kinds of animal putrescence. 

Alloy of Sodium and Potassium. 10 parts of potassium, 



236 Metals. — Lithium. 

and 1 of sodium, form an alloy which is liquid at zero, Fahr 
and is lighter than naphtha, or rectified petroleum. 



LITHIUM. Symb. L. Equiv. 6.44. 

This substance was obtained by Davy, by means of gai 
vanism, as a white-colored metal, like sodium ; but it oxidized 
so rapidly that he was unable to examine its properties 

Compounds of Lithium. 

Protoxide of Lithium, Lithia, (L-j-O. 14.44,) was dis- 
covered, in 1818, by M. Arfvvedson, in the mineral petalite; 
it exists in spodumene, lepidolite, and several varieties of 
mica. 

Process. One part of petalite to two of fluor-spar are 
finely pulverized, and the mixture heated with four times 
its weight of sulphuric acid, till the acid vapors are disen- 
gaged. Sulphate of lithia and alumina are formed. These 
salts are then dissolved in water, and boiled with pure am- 
monia, to precipitate the alumina; filter and evaporate to dry- 
ness, and then expel the sulphate of ammonia by a red heat. 
The result is a pure sulphate of lithia, which must be 
decomposed by acetate of baryta, and the acetate, by a red 
heat, is converted into the carbonate, and this reduced to the 
caustic hydrate, by boiling it with lime. 

Properties. Similar to potassa and soda in its alkalinity 
and chemical relations. It is distinguished from them by its 
greater neutralizing power ; when exposed to the air, it ab- 
sorbs carbonic acid, and becomes opaque. 

Chloride of Lithium (L-j-Cl. 41.86) is obtained by dissolving lithia 
in hydrochloric acid, evaporating to dryness, and fusing the residue. 

Properties. A white, semi-transparent solid, and, like 
the chlorides of potassium and sodium, forms, by evaporation, 
colorless, anhydrous, cubic crystals, which differ from those 
chlorides in being very deliquescent, dissolving freely in 
water and alcohol, and tinging the flame of alcohol red. 

Fluoride of Lithium, (L-f-F. 25.12,) prepared by dissolving lithia m 
hydrofluoric acid, and is a very fusible solid. 



Barium 237 



Sect. 2. Metallic Bases of the Alkaline Earths, 

BARIUM. Symb. Ba, Equiv. 68.7. 

Barium was discovered by Davy, in 1808. 

Process. The process consisted in forming the carbonate 
of baryta into a paste with water, placing a globule of mer- 
cury in a small hollow made in its surface, and laying the 
paste on a platinum tray, which communicated with the posi- 
tive pole of a galvanic battery of 100 double plates, while the 
negative wire was in contact with the mercury. The baryta 
was decomposed, and its barium entered into combination 
with the mercury. This amalgam was heated in a vessel 
free from air, by which means the mercury was expelled, 
and the barium obtained in a pure state. — T. 

Properties. The metal, thus obtained, has a dark gray 
color, with a lustre inferior to cast iron. It is much heavier 
than water ; it even sinks in sulphuric acid. Its attraction 
for oxygen is scarcely less than that of the preceding metals ; 
is converted into baryta by exposure to the air ; decomposes 
water with effervescence, from the escape of hydrogen gas. 
It has been obtained but in small quantities, and its proper- 
ties are not accurately defined. 

Compounds of Barium. 

Protoxide of Barium, or Baryta, (Ba-j-O. 76.7,) was 
discovered by Scheele, in 1774, and called barytes or baryta, 
from the great density of its compounds. 

Process. It is the sole product of the oxidation of barium 
in the air and in water. It is also obtained by exposing the 
nitrate of baryta to a red heat, or the carbonate, mixed with 
charcoal, to an intense white heat. 

Properties. Baryta is a gray powder, (sp. gr. 4,) very dif- 
ficult of fusion ; has a sharp, caustic, alkaline taste, with 
other alkaline properties ; insoluble in alcohol, but has a 
strong affinity for water, and slacks like lime, but with the 
evolution of more intense heat, and is converted into a white, 
bulky hydrate, which fuses at a red heat, but cannot be 



238 31etals. — Compounds of Barium. 

deprived of its water at the highest temperature of a smith's 
forge. A saturated solution yields, on evaporation, trans- 
parent, flattened, prismatic crystals, containing 10 atoms of 
water to 1 of baryta. 

This solution is an excellent test of carbonic acid, or other 
gaseous mixtures in the atmosphere. The acid gives a 
milky appearance to the clear solution, due to the solid car- 
bonate of baryta, which is precipitated. 

Distinguished by the fact, that all its soluble salts are 
precipitated by alkaline carbonates, and by the insoluble 
sulphate, which latter cannot be separated by any other acid. 

Binoxide of Barium (Ba-{-20. 84.7) is formed by conducting dry 
oxygen gas over pure baryta, at a red heat. It is a grayisb-vvhite sub- 
stance, employed by Thenard in obtaining the binoxide of hydrogen. 

Chloride of Barium (Ba-f-Cl. 104.12) is prepared by decomposing a 
solution of sulphuret of barium with hydrochloric acid, or by conduct 
ing chlorine gas over baryta, at a red heat. On concentrating the solu- 
tion, the chloride crystallizes in flat, four-sided tables, beveled at the 
edges like crystals of heavy-spar. They consist of 1 eq. of the chlo- 
ride to 2 of water. 

Properties. Pungent and acrid to the taste. The crys- 
tals do not change in moist air ; but in a very dry air, at 60° 
they lose their water of crystallization, and are rendered 
anhydrous at a full red heat ; decomposed by sulphuric acid 
and alkaline carbonates. 

Iodide of Barium (Ba-f-I. 195) is formed by acting on 
baryta with hydriodic acid, and evaporating the solution. 
Soluble in water, and forms colorless, needle-shaped crystals. 

Bromide of Barium (Ba-{-Br. 147.1) is prepared by 
boiling protobromide of iron with moist carbonate of baryta, 
evaporating the filtered solution, and heating the residue to 
redness. The product crystallizes, by careful evaporation, 
in white rhombic prisms, which have a bitter taste, are 
slightly deliquescent, and soluble in water and alcohol. — T. 

Fluoride of Barium (Ba-f-F. 87. 3S) is prepared by 
digesting moist carbonate of baryta in hydrofluoric acid. It 
is a white powder, soluble in nitric and hydrochloric acids. 

Sulphuret of Barium (Ba-j-S. 84.8) is prepared by pass- 
ing dry hydrosulphuric acid over pure baryta, at a red heat. 
It dissolves readily in hot water, and deposits colorless 
crystals on cooling. It may be employed for obtaining pure 
baryta by a process described by Turner, 5th ed. p. 308 



Strontium. 239 

Cyanide of Barium (Ba-j-Cy* 95.09) is procured by 
the action of hydrocyanic acid on baryta. It is slightly 
soluble in water, has an alkaline reaction, and is decomposed 
by the carbonic acid of the air. 

Sulphocyanide of Barium -(Ba + CyS 2 . 127.29) is ob- 
tained in the same way as the sulphocyanide of potassium. 
It is very soluble in water, and crystallizes in beautiful 
needles, slightly deliquescent. 

Phospkvret of Barium is formed by heating to redness anhydrous 
caustic baryta, and throwing into it pieces of phosphorus. It decom- 
ooses water, and forms phosphuret of hydrogen. 



STRONTIUM. Symb. Sr. Equiv. 43.8. 

Strontium was discovered by a process similar to that for 
barium, which it resembles in most of its properties ; oxi- 
dizes in the air ; decomposes water, by which process it is 
converted into strontia. 

Compounds of Strontium. 
Protoxide of Strontium (Sr-j-O. 51.8) was discovered 
by Dr. Hope, in 1792 ; also by Klaproth. 

Process. It was formerly extracted from strontianite, (a 
carbonate of strontia,) found at Strontian, in Scotland; 
hence its name. It may be prepared from the nitrate or 
carbonate of strontia, in the same manner as baryta. 

Properties. It resembles baryta in most of its properties. 
A gray substance, pungent and acrid to the taste ; slacked 
with water, it produces intense heat, and is converted into a 
hydrate which fuses readily, but the highest temperature of 
a blast furnace will not separate the water; soluble in boil- 
ing water, and crystallizes on cooling. The solution, like 
baryta, is an excellent test of carbonic acid. 

Peroxide of Strontium (Sr-(-20. 59.8) is prepared in the 
same way as the peroxide of barium, and, like it, is em- 
ployed to form binoxide of hydrogen ; decomposed by dilute 
acids into strontia and oxygen. It is white, of a brilliant 
Justre, inodorous, and nearly tasteless. 

Chloride of Strontium (Sr-}-Ci. 79.22) is obtained in a 
manner precisely similar to the chloride of barium; crys- 



i 

240 Metals. — Calcium 

tallizes from its solutions in colorless prismatic crystals,, 
which are distinguished from baryta by being soluble in twice 
their weight of water at 60°, and by the red tinge which it 
gives to the flame of an alcoholic solution. The anhydrous 
chloride fuses at a red heat, and yields a white, crystalline, 
brittle mass on cooling. — T. 

Iodide of Strontium (Sr-f-I- 170.1) is prepared in the same manner 
as iodide of barium. It is very soluble in water, fuses without decom- 
position in close vessels, but is resolved into iodine and strontia, by a 
red heat, in the open air. 

Fluoride of Strontium (Sr-f-F. 62.48) is obtained in the same way as 
the fluoride of barium. It is a white powder, sparingly soluble. 

Protosulphuret of Strontium (Sr-}-S. 59.9) is similar in its proper- 
ties, and modes of preparation, to the corresponding compound of 
barium 

CALCIUM. Symb. Ca. Equiv. 20.5. 

Calcium was discovered by Davy, in 1808, by exposing 
lime to the action of the galvanic battery. 

Properties. It is of a whiter color than barium, and ig 
converted into lime by oxidation. Its other properties are 
unknown. 

Compounds of Calcium. 

Protoxide of Calcium (Ca -f- O. 28.5) is generally obtained 
by burning common limestone (carbonate of lime) in kilns, 
for three or four days, to expel the carbonic acid. It ia 
then called lime, or quick lime. The purest lime is prepared 
from the Iceland spar, or Carrara marble. 

Properties. A brittle, grayish-white, earthy solid, of an 
acrid, caustic, and alkaline taste ; sp. gr. 2.3 ; difficult of fusion, 
but promotes the fusion of other bodies, and is hence used 
as a flux in smelting the ores of the metals. It has a strong 
affinity for water, with which it combines with the disengage- 
ment of heat, and forms the hydrate — a bulky, white sub- 
stance, called slacked lime. This parts with its water at a 
red heat, and is more soluble in cold than in hot water. 

Lime Water. This is simply a solution of the hydrate, and 
possesses similar properties, absorbs carbonic acid from the 
air, and should therefore be kept in close vessels. It is a 



Compounds of Calcium. 241 

most delicate test of carbonic acid — a property already no- 
ticed under carbon. 

Uses. The uses of lime are well known for a cement, for 
plaster, and as an anti-acid in medicine ; a substance almost 
indispensable in every civilized country, and hence the Cre- 
ator has made it very abundant and widely diffused, (the 
carbonate forming ^ part of the crust of the globe.) 

Peroxide of Calcium (Ca-f-20. 36.5) is similar in prop- 
erties, and in the mode of preparation, to the peroxide of 
barium. 

Chloride of Calcium (Ca -f- CI. 55.92) exists in sea-water 
and some saline springs, and may be formed by dissolving 
marble in hydrochloric acid. On evaporation, the solution 
yields colorless prismatic crystals, which consist of 10 equiv. 
of water to 1 of the chloride ; these are rendered anhydrous 
by heat, and fuse at a red heat, but absorb the water again 
from the air, and deliquesce, owing to their strong attraction 
for water. It is much used for freezing mixtures with snow. 
Soluble in alcohol, with which it forms a definite compound. 

Iodide of Calcium (Ca -f- I. 146.8) is prepared by digesting 
hydrate of lime with protiodide of iron. It is a white, fusible 
compound, deliquescent, and very soluble in water; the solu- 
tion will dissolve a large quantity of iodine, and, on evapo- 
ration, yield the periodide of calcium, in black prismatic 
crystals. 

Bromide of Calcium (Ca-|-Br. 98.9) is prepared in the 
same manner as the iodide, which it resembles in its prop- 
erties. 

' Fluoride of Calcium. Ca-|-F. 39.18. This is an abundant 
natural product, generally called fluor-spar or Derbyshire 
spar. It occurs in beautiful cubic crystals, the primary form 
of which is an octohedron, used extensively for ornamental 
purposes, and is justly celebrated for the vari?ty and beauty 
of its colors ; fuses at a red heat, insoluble in water, and is 
decomposed by sulphuric acid; thrown in coarse powder on 
hot iron, it emits beautiful phosphorescent light, varying from 
red to purple and green. 

Protosulphuret of Calcium (Ca + S. 36.6) may be pre- 
pared by exposing sulphate of lime to a strong heat in a 
charcoal crucible. It is white, with a reddish tint, and pos- 
sesses the remarkable property of becoming phosphorescent 
by exposure to the light It is the essential ingredient in 
Canton's phosphorus. 
11 



242 Metals. — Magnesium. 

Bisulphuret of Calcium (Ca-f-2S. 52.7) occurs in orange-col orea 
crystals, prepared by boiling 3 parts of slacked lime, 1 of sulphur, ana 
20 of water, for a few hours, and setting the solution aside in bottles 
corked tight for several days. When either of the above solutions is 
boiled with sulphur, the solution contains calcium, with 5 equiv. of 
sulphur — the quintosulphuret of calcium, (Ca-f--5S. 101.) 

Phosphuret of Calcium (Ca -}-P. 36.2) is formed by passing the vapoi 
of phosphorus over quick lime, at a low red heat. It is a brown sub- 
stance, and, when thrown into water, forms, by mutual decomposition, 
phosphuretcd hydrogen, hypophosphorous acid, and phosphoric acid. 

Chloride of Lime. Ca + O + Cl. 63.92. This substance, 
commonly called oxymuriate of lime, or bleaching powder, is 
prepared by exposing recently-slacked lime to an atmosphere 
of chlorine. The gas is rapidly absorbed, and enters into 
direct combination with the lime, although Dr. lire thinks 
that no definite compound is formed. 

Properties. A dry, white powder, similar to quick lime, 
having the odor of chlorine, which it readily yields up when 
moistened with water ; possesses powerful bleaching proper- 
ties, for which purpose it is extensively used in the arts. 
The strength of the chloride is estimated by the quantity of 
indigo which a given portion of the bleaching solution will 
deprive of its color. Used also in medicine, as a disinfecting 
agent ; it should be kept in every family. 



MAGNESIUM. Symb. Mg. Equiv. 12.7. 

Magnesium was discovered and obtained in small quantities 
by Sir H. Davy, by means of galvanism ; but M. Bussy, in 
1S30, obtained it in greater abundance by the action of po- 
tassium on chloride of magnesium. 

Process. For this purpose, five or six pieces of potassium, 
of the size of peas, were introduced into a glass tube, the 
sealed extremity of which was bent into the form of a retort, 
and upon the potassium were laid fragments of chloride of 
magnesium; the latter being then heated to near its point of 
fusion, a lamp was applied to the potassium, and its vapoi 
transmitted through the mass of the heated chloride. Vivid 
incandescence immediately took place; and, on putting the 
mass, after cooling, into water, the chloride of potassium, with 
undecomposed chloride of magnesium, was dissolved, and 
metallic magnesium subsided. — T. 



Compounds of Magnesium. 243 

Properties. A very malleable solid, of a white color, like 
Bilver, and of a brilliant, metallic lustre. Dry, air and water 
do not oxidize it, but moist air does; heated to redness in 
oxygen gas, it burns vividly, and forms magnesia. In chlo- 
rine gas it inflames spontaneously. 

Compounds of Magnesium. 

Protoxide of Magnesium, (Mg-(-0. 20.7,) commonly known 
by the name of magnesia, is prepared by exposing the car 
bonate to a strong heat, to expel the carbonic acid. 

Properties. A white, infusible powder, of an earthy appear- 
ance, without taste or odor; sp. gr. 2.3; very infusible, and 
sparingly soluble in water, requiring 5142 times its weight 
at 60°, and 36,000 of boiling water to dissolve it. The prod- 
uct is a hydrate. It changes vegetable infusions slightly, 
but possesses the properties of an alkali, by forming neutral 
salts with acids ; absorbs water and carbonic acid from the 
air, and should be kept in close bottles. It exists in nature 
in serpentine, steatite, magnesite, and in sea-water, in con- 
siderable abundance. 

Chloride of Magnesium (Mg-j-Cl. 48.12) is prepared by 
dissolving magnesia in hydrochloric acid, evaporating to dry- 
ness, mixing the residue with its own weight of hydrochlorate 
of ammonia, and projecting the mixture, in successive portions, 
into a platinum crucible, at a red heat. The ammonia is 
expelled, and the chloride remains a transparent, colorless 
mass ; very deliquescent, and soluble in water and alcohol. 

Iodide of Magnesium (Mg-f-L 139) is formed by dissolving magnesia 
m hydriodic acid ; known only in solution with water. 

Bromide of Magnesium (Mg-{-Br. 91.1) is prepared by dissolving 
magnesia in hydrobromic acid. It occurs in small acicular crystals, 
of a sharp taste, very deliquescent and soluble; it is decomposed by a 
strong heat. 

Fluoride of Magnesium (Mg-f-F. 31.38) i3 formed by digesting mag- 
nesia in excess of hydrofluoric acid ; it is insoluble, and bears a red heat 
Without decomposition. 



244 Metals. — Aluminium. 

Sect. 3. Metallic Bases of the Earths. 

ALUMIJYIUM. Symb. Al. Equiv. 13.7. 

Sir H. Davy proved that alumina was an oxidized body 
and Wohler succeeded in decomposing it, from which he ot> 
tained the pure metal, aluminium. 

Process. This metal may be obtained by heating the 
chloride of aluminium with potassium in a covered platinum 
or porcelain crucible. Intense heat is evolved during the 
orocess. After cooling the mass, it is put into water, by 
which the saline matter is dissolved ; hydrogen gas, of 
an offensive odor, is evolved, and a gray powder subsides. 
This powder, after being washed in cold water, is pure 
aluminium. 

Properties. Aluminium, as thus prepared, is a gray powder, 
similar to platinum, but when rubbed in a mortar, exhibits 
distinctly a metallic lustre. Fuses at a higher temperature 
than cast iron, and in this state is a conductor of electricity, 
but a non-conductor when cold. 

Exp. Heated in the air to redness, it burns brilliantly, and forms 
alumina ; but when introduced into oxygen gas, at a red heat, it burns 
v/ith such splendor, that the eye can hardly support the light, and with 
so much heat, that the resulting alumina is partially fused into yellow 
fragments, as hard as corundum, which not only scratch, but abso- 
lutely cut glass. 

Exp. Takes fire in chlorine gas at a red heat, but is not oxidized by 
water at common temperatures, nor attacked by cold sulphuric and 
nitric acids; soluble in solutions of potassa and ammonia, and in hot 
sulphuric, or dilute sulphuric and hydrochloric acids. 

Compounds of Aluminium. 

Sesquioxide of Aluminium (2A1 + 30. 27.4 + 24 == 51.4) 
is the only known oxide of aluminium, and is commonly 
called alumina, or aluminous earth. 

Natural History. Alumina is very abundant in nature, 
being found in every region of the globe, and in rocks of ah 
ages ; hence it is one of the principal ingredients in most 
soils. The different kinds of clay of which bricks, pipes, and 
earthen-ware are made, consist mostly of hydrate of alumina, 



Compounds of Aluminium. 245 

It is also found beautifully crystallized, in some of the most 
beautiful gems. The ruby and the sapphire are nearly pure 
alumina 

Process. It may be prepared for chemical purposes from 
alum, which is a sulphate of alumina and potassa. Dissolve 
pure alum in water, and precipitate the alumina by carbonate 
of ammonia. This, when washed in hot water and filtered, 
is the hydrate, which may be rendered pure by a white heat. 
An easier process is to expose the sulphate of alumina and 
ammonia to a strong heat, so as to expel the ammonia and 
sulphuric acid. M. Gaudin has succeeded in forming rubies, 
by mixing ammoniacal alum with -3-^3- part of chromate of 
potassa, and exposing to a high heat. 

Properties. Inodorous, tasteless, and possesses the proper- 
ties both of an acid and an alkali ; insoluble in water, but has 
a powerful affinity for it ; when moistened, it forms a ductile 
mass, which gives it its great utility in the arts. It is a re- 
markable exception to the law, that heat expands all bodies 
There are probably several hydrates of alumina. 

Uses. Used for bricks, and various kinds of pottery. 

Sesquichloride of Aluminium (2A1 -|-3C1. 133.66) was dis- 
covered by Wohler, by transmitting dry chlorine gas over a 
mixture of alumina and charcoal, heated to redness. It is of 
a paje, greenish-yellow color, partially translucent, of a highly 
crystalline, lamellated texture, somewhat like talc, but with- 
out regular crystals. On exposure to the air, it fumes slightly, 
emitting an odor, like hydrochloric acid gas. 

Exp. When thrown into water, it is speedily dissolved with a hiss- 
ing noise, and so much heat is evolved, that the water, if in small 
quantities, is brought into a state of brisk ebullition, and forms the 
kydrochl 'orate of alumina. 

Scsquisulphuret of Aluminium (2A1-J-3S. 75.7) is prepared by drop- 
ing a piece of sulphur on to aluminium, strongly heated. It is a vitri- 
fied, semi-metallic substance, of a dark color. 

Sesquiphosphuret of Aluminium (2Al-f- 3P. 74.5) is formed by heat- 
ing aluminium in contact with the vapor of phosphorus ; it is a black- 
<sh-gray, pulverulent mass, which, by friction, acquires a dark gray 
metallic lustre, and, in the air, has the odor of phosphursted hy- 
Jrogen. 

Sesquiseleniuret of Aluminium (2Al-r-3Se. 146.2) is obtained by 
hrating to redness a mixture of selenium and aluminium. It is a 
black, pulverulent substance, which acquires a metallic lustre when 
fubbed. 



246 Metals. — Glucinium — Yttrium. 



GLUCINIUM. Symb. G. Equiv. 26.5. Sp. gr. 3. 

Glucinium was obtained by Wohler, in 1828, by the action 
of potassium upon the chloride of glucinium. The process is 
similar to that for obtaining aluminium. It appears in the 
form of a gray powder, which acquires the metallic lustre by 
burnishing, and is easily oxidized. 

Sesquiozide of Glucinium, or Glucina, (2G-|-30. .77,) 
was discovered by Vauquelin, in 1798. It is found only in 
the minerals emerald, beryl, and euclase. 

Process. It is obtained by exposing beryl in fine powder 
with three times its weight of carbonate of potassa, to a strong 
red heat. The fused mass is dissolved in dilute hydrochloric 
acid, evaporated to dryness, re-dissolved in acidulated water, 
and the alumina and glucina are thrown down by ammonia , 
the precipitate macerated by carbonate of ammonia, which 
dissolves the glucina, and on boiling the filtered liquor, car- 
bonate of glucina subsides ; the carbonic acid is then expelled 
by a red heat. 

Properties. A white powder, without taste or odor, quite 
insoluble in water. Pure potassa or soda precipitates it from 
its salts; distinguished from alumina by being precipitated 
from its solution with carbonate of ammonia, when the solu- 
tion is boiled. 

YTTRIUM. Symb. Y. Equiv. 32.2. 

Yttrium was prepared by Wohler, in 1828, by a process 
similar to that for obtaining glucinium. 

Properties. It has a scaly texture, a grayish-black color, 
and a perfectly metallic lustre. It is a brittle metal, and 
burns with splendor in common air, and with still greater 
brilliancy in oxygen gas. The result of this combustion is 
the earth yttria, which was discovered in 1794, by Gadolin, 
m a mineral at Ytterby, Sweden. It is of a white color, 
soluble in sulphuric acid, and combines with sulphur, sele- 
nium, and phosphorus. Its salts have a sweetish taste and 
some of them have an amethystine color 



Thorium — Zirconium. 247 

THORIUM. Symb. Th. Equiv. 59.6. 

This metal was procured by the action of potassium on the 
■hloride of thorium; decomposition being accompanied by a 
ilight detonation. On washing the mass, thorium is left, in 
.he form of a heavy, metallic powder, of a deep leaden-gray 
color ; and, when pressed in an agate mortar, it acquires 
metallic lustre and an iron-gray tint. — T. 

Properties^ Thorium is not easily oxidized at common 
temperatures, but burns with great brilliancy in the air. It 
is not acted upon by alkalies, scarcely at all by nitric, and 
slowly by sulphuric acid; but is readily dissolved by hydro- 
chloric acid, with the disengagement of hydrogen gas. 

Protoxide of Thorium, or Thorina, (ThO. 67.6,) was dis- 
covered by Berzelius, in 1828, in a rare mineral from Nor- 
way, called thorite. It is a white, earthy substance, soluble 
in none of the acids, except the sulphuric, and is precipitated 
from its solutions by the caustic alkalies as a hydrate, in 
which state it absorbs carbonic acid from the atmosphere, 
and dissolves in acids. 

It is distinguished from alumina and glucina, by its insolu- 
bility in pure potassa, and from yttria, by forming with sul- 
phate of potassa a double salt, insoluble in a cold, saturated 
solution of sulphate of potassa. 



ZIRCONIUM. Symb. Zr. Equiv. 33.7. r 

Zirconium was discovered by Berzelius, in 1824. 

Process. It is obtained by heating the double fluoride oi 
zirconia and potassa, carefully dried and mixed with potassium, 
in a glass or iron retort. The mass is then washed in hot 
water, and digested for some time in hydrochloric acid. 

Properties. This substance exists in the form of a black 

powder. It may be pressed out into thin, shining scales, but 

its particles adhere very slightly. It is a non-conductor of 

electricity. It takes fire, when heated in the open air, at a 

temperature below a red heat ; the product is zirconia. 

Sesquioxide of Zirconium, or Zirconia, (2Zr-f-30. 91.4,) was dig- 
lovered by Klaproth, in 1789, from the Zreon, or Jargon, of Ceylon. 



M8 Metals. — Manganese. 

17 parts of this substance, finely pulverized, and mixed with 21 of 
litharge, may be fused, and a glass obtained, soluble in acids, from 
which the zirconia is derived ; or it can be formed directly by the com- 
bustion of the metal in oxygen or common air. 

Properties. A fine, white powder, inodorous and taste- 
less ; sp. gr. 4 ; exposed to a strong heat, it fuses, assuming a 
light gray color ; when cool, it is so hard as to strme fire with 
steel, and to scratch quartz crystal. 



Order II. Metals, the Oxides of which are neither 
Alkalies nor Earths. 

Sect. 1. 3Ietals which decompose Water at a red Heat 

MANGANESE. Symb. Mn. Eq. 27.7. Sp.gr. 8.013. 

History. In 1774, Scheele described the black oxide of 
manganese as " a peculiar earth." Gahn subsequently dis- 
covered that it contained a new metal, to which he gave the 
name of magnesium, a term applied afterwards to the metallic 
base of magnesia ; and for which the words manganesium and 
manganium have been substituted. The metal is not found 
in the native or uncombined state, but its oxides are very 
abundant. 

Process. Make a paste with finely-pulverized oxide of 
manganese and oil, and expose it to the heat of a smith's 
forge, in a Hessian crucible, lined with charcoal, for the 
space of two hours. 

Properties. A hard, brittle metal, of a grayish-white color, 
and granular texture; very infusible; not attracted by the mag- 
net, except when it contains iron ; soon tarnishes on exposure 
to the air, and absorbs oxygen rapidly when heated to redness. 
Decomposes water slowly at common temperatures, but rapidly 
at a red heat. 

Compounds of Manganese. 

Protoiide of Manganese (Mn -j- O. 35.7) may be formed, 
as shown by Berthier, by exposing the peroxide, sesquioxide 
or red oxide of manganese, to the combined agency of char 



Compounds of Manganese, 249 

Cv>ai, and i white heat; or by exposing either of the oxides, 
contained in a glass lube, to a current of hydrogen gas, at an 
eWated temperature. 

Properties. When pure, it is of a light green, or moun- 
tain-green color, undergoing little if any change in the open 
air, but oxidizes rapidly at 600° Fahr., and is instantly 
converted into the red oxide, at a low red heat, and some- 
times takes fire. It is the salifiable base of the metal, and is 
contained in all its salts; hence its strong amnity-for acids. 

Sesquioxide of Manganese (2Mn-f-30, or Mn-f-l^O. 79.4) occurs 
nearly pure in nature, and may be formed by exposing the peroxide to 
a red heat. It is the chief residue of the usual process of obtaining 
oxygen gas, but it is difficult to regulate the heat so as to obtain it in a 
pure state. 

Properties. The color is brown or black, according to 
the source from which it is obtained ; unites with nitric and 
sulphuric acids, and is converted, by exposure to the air, into 
the peroxide. 

Peroxide of Manganese. Mn -f- 20. 43.7. This is a well- 
known native product, commonly called black oxide of man- 
ganese. 

Properties. It occurs generally in masses, of an earthy 
appearance, and black color, mixed with other substances ; 
but it is frequently found in small prismatic crystals. It is 
not affected by exposure to the air or water, but yields oxy- 
gen when heated to redness, and is the substance most 
generally employed for that purpose, (see page 130;) does 
not unite with acids or alkalies. 

Uses. Employed in the arts for coloring glass, in prepar- 
ing chlorine gas, and in forming the salts of manganese. 

Red Oxide of Manganese. 3Mn + 40. 115.1. This is 
identical with the oxidum manganoso-manganium of Arfwed- 
gon, and occurs as a natural product. It may be formed arti- 
ficially by exposing the peroxide or sesquioxide to a white heat. 

Properties. Color, when finely rubbed, is nearly black 

when warm, and brownish-red when cold. It is permanent 

in the air at all temperatures, dissolves in small quantities by 

cold sulphuric acid, and more rapidly by the aid of chlorine; 

11* 



250 Metals. — Manganese. 

the solution has an amethystine tint. It is the cause of tha 

rich color of the amethyst. 

Varvicite. 4Mn-f-70. 166.8. Sp. gr. 4.531. Known only as a 
natural production, and first noticed by Mr. Phillips among some ores 
of manganese, found at Hartshill in Warwickshire. It resembles' the 
peroxide in color, for which it was first mistaken, but may be distin 
guished from it by its stronger lustre, greater hardness, more Jainel 
iated texture, and by yielding water when heated to redness. It ia 
probably, like the red oxide, a compound of two oxides, consisting of 
2 equivalents of the peroxide, and 1 of the sesquioxide of manganese, 
with 1 of water. — T. 

Manganic Acid. Mn-f-30. 51.7. When peroxide of 
manganese is mixed with equal weights of nitre, or carbon- 
ate of potassa, and heated to redness, it fuses, and a green- 
colored mass is formed, known by the name of mineral 
chameleon, from the property of its solution to pass through 
several shades of color. 

Exp. On the addition of cold water, a green solution is formed, 
which soon becomes blue, purple, and red ; and ultimately a brown, 
flocculent matter — hydrated peroxide of manganese — subsides. — T. 

Theory. These changes are owing to the formation of 
manganate of potassa, of a green color, which passes to the 
permanganate of potassa, which is red, the blue and purple 
being due to a mixture of these compounds; but the man- 
ganic acid has not been obtained in a separate state, owing 
to its ready decomposition. 

Permanganic Acid. 2Mn-j-70. 111.4. This acid is 
more permanent, though easily decomposed, even by contact 
with paper or linen in filtering. It may be obtained from 
the permanganate of baryta, by sulphuric acid. 

Properties. Color red ; decomposed by water at 86° ; col- 
oring matter is bleached by it, but particles of organic matter 
floating in the air decompose it rapidly. 

Protochloride of Manganese (Mn-f-Cl. 63.12) is prepared by evap 
orating a solution of the chloride to dryness, and heating it to redness 
in a glass tube, while a current of hydrochloric acid gas is transmitted 
through it ; fuses at a red heat, and forms a pink-colored lamellated 
mass on cooling; deliquescent, and very soluble in water. — T. 

Perchloride of Manganese (2Mn -f-^Cl. 303.34) was discovered by 
Dumas, and formed by putting a solution of permanganic into sul- 
phuric acid, and adding fused sea-salt. 

Properties. When first formed, it is a greenish-colored 
vapor ; but by passing it through a glass tube cooled to -5°, 



Iron. 251 

it condenses into a greenish-brown liquid, decomposed in 
stantly by water. 

Perfluoride of Manganese (2Mn-j-7F. 186.16) was discovered by 
Dumas and Wdhler. Prepared by mixing the mineral chameleon with 
half its weight of fluor-spar in a platinum vessel, and decomposing the 
mixture with fuming sulphuric acid. 

Properties. A yellowish-green gas, or vapor, w T hich ac- 
quires a beautiful purple-red color when mixed with air; 
freely absorbed by water, giving to the solution the same red 
tint; acts on glass with the formation of fluosilicic acid gas, 
and the deposition of a brown matter, which acquires a deep 
purple-red tint by the addition of water. 

Protosulphuret of Manganese (Mn-f-S. 43.8) is found native in 
Cornwall, England, and may be formed by igniting the sulphate with 
one sixth of its weight of charcoal, in powder. 

Cyanide of Manganese. Mn-j-Cy. 27.7 -f- 26.39= 54.09, equi v. 

Pkosphuret and Carburet of Manganese may be obtained by heating 
the metal in contact with phosphorus or carbon. 

Alloys of Manganese. Manganese unites with several of 
the metals, forming alloys of little importance. 



IROjY. Symb. Fe. Equiv. 23. Sp. gr. 7.78. 

History. Iron is decidedly the most important and useful 
of the metals. It appears essential to a state of civilization ; 
hence it is the most abundant, and widely diffused throughout 
different parts of the earth. Hence, too, it seems to have 
been made known to the first inhabitants of the earth, and 
used in all ages where men have emerged even to the state 
of barbarians. It was formerly called Mars. 

Natural History. Iron is rarely found pure in nature 
Even meteoric iron is alloyed with cobalt and nickel ; but its 
oxides are very abundant. In combination with oxygen and 
sulphur, it is so widely diffused, that few minerals can be 
*ound that do not contain traces of it. It enters also into 
plants and animals. The ores of iron are the red oxides, 
including red and brown hematite, the black oxide, or mag- 
netic iron ore, and the carbonate of the protoxide, either pure 
or in the form of clay iron ore. 

process. The extraction of the iron from the ores is ef« 



%58 Metals. — ■ Iron. 

fected by subjecting them, after being roasted and reduced t<? 
a coarse powder, to the action of charcoal, lime, and caloric; 
this is the cast iron, which contains some impurities, es- 
pecially carbon. The malleable or wrought iron is prepared 
from this, by continuing the process until the carbonaceous 
matter is burned out ; it then becomes solid again, and ia 
put under a roller or hammer and drawn out into bars. 
Steel is the wrought iron combined with carbon. The best 
wrought-iron bars are surrounded by dry charcoal and heated 
to a high temperature. 

Properties. Iron has a peculiar gray color, and strong 
metallic lustre, which is brightened by polishing, of which it 
is capable of receiving a higher degree than any other metal. 
It is less ductile and malleable than some others, but the most 
tenacious of all; hence it may be drawn out into fine wire, 
but not into thin leaves. Its texture is fibrous, and when 
heated, is soft, and possesses the property of being welded to 
other heated iron. When cooled suddenly, it is brittle, but 
may be rendered malleable again by heat ; it is very infusible^ 
and when combined with carbon, very hard. In this state, 
it is capable of being made permanently magnetic: it is the 
great repository of natural magnets, and the only substance, 
save cobalt and nickel, which possesses magnetic properties. 

Its uses in the arts are well known. 

Compounds of Iron. 

Protoxide of Iron. Fe-j-O. 36. The existence of this ox- 
ide was first inferred by Gay Lussac; but Stromeyer obtained 
it in an insulated form, by transmitting dry hydrogen gas 
over the proxide at a low temperature. It may also be 
precipitated from its salts as a white hydrate by pure alkalies, 
as a carburet by a^ialine carbonates, as a white ferrocyanuret 
by ferrocyanuret of potassium, and as a protosulphuret by 
alkaline hydrosulphates. 

Properties. Color dark blue, and communicates a blue 
tint to substances melted with it. It is magnetic, and so 
combustible, that it takes fire spontaneously in the open air, 
and is converted into the peroxide. Its salts absorb oxygen 
bo rapidlv from the air, as to be useful in eudiometry. It is 



Compounds of Iron. 253 

the base of the native carbonate, and the green vitriol of 
commerce. 

Peroxide of Iron. 2Fe + 30 or Fe + lJO. 80. This is the 
red hematite of mineralogists, a very abundant natural pro- 
duction. 

Process. It is made chemically by dissolving iron in nitro- 
hydrochloric acid, and adding an alkali. 

The precipitate is of a brownish color, and is identical with 
the mineral called brown hematite, and consists of 1 equiv- 
alent of the peroxide and 2 of water. 

Properties. It is a brownish-red compound, not attracted 

by the magnet. It is precipitated from its salts by the pure 

alkalies. * With ferrocyanuret of potassium it forms Prussian 

blue ; with infusion of nutgalls it forms ink. 

Tests of the presence of iron in any composition, may be made by 
boiling it with nitric acid, which converts the iron into the peroxide ; 
the ferrocyanuret of potassium will then form a blue precipitate. 

Black Oxide. (Fe + 0) + (2Fe-f-30.) 116. This com- 
pound is called, by Berzelius, oxidum ferroso-ferricum, and 
is supposed to be a mixture or combination of the two pre- 
ceding oxides. 

It occurs native, often in regular octohedral crystals. It 
is formed also when iron is heated in the open air, or in con- 
tact with moisture. It is not only magnetic, but is itself 
often a magnet. With sulphuric acid, an olive-colored so- 
lution is formed, containing two salts, the sulphate of the 
protoxide, and peroxide, which may be separated from each 
other by means of alcohol. The black oxide is the cause 
of the green color of glass. 

ProtochJoride of Iron (Fe -f- CI. 63.42) is formed by dissolving iron 
in hydrochloric acid, evaporating to dryness, and heating the product 
to redness, in a tube deprived of air. It is a gray, crystalline substance, 
fusing at a red heat, and is easily converted into i .e hydrochlorate of 
..he protoxide of iron. 

Perchlorideof Iron (2Fe-(-3Cl. 162.26) is formed by the combustion 
of iron in chlorine gas. It is a yellowish-brown substance, crystal- 
lizes in small iridescent plates, of a red color ; volatilizes at little aoove 
21.2P; deliquesces readily, and dissolves in water, alcohol, and ether, 
and is converted by water into the hydrochlorate of the peroxide of 
iron. 

Protiodide of Iron (Fe-j-I- 154.3) is prepared by digest- 



$54 Metals. — Iron. 

ing iodine in water and iron wire. On evaporating the so!u« 
tion to dryness, without exposure to the air, and heating ft 
moderately, it yields crystals of an iron-gray color and metal- 
lic lustre, deliquescent, very soluble in water and alcohol 
and used in medicine as a tonic. 

The Periodide of Iron (2F-J-3I. 434.9) is obtained by exposing a so 
lution of the protiodide to the air. It is a volatile, red compound, solu 
ble in water and alcohol. 

The Protobr omide of Iron (Fe-J-Br. 106.4) and the Perbromide of 
Iron (2Fe -4-3Br. 291.2) are formed in a similar manner with the iodides 
and have similar properties. Protofluoride of Iron. Fe -4-F. 46.68. 

Perfluoride of Iron (2Fe -j- 3F. 112.04) is formed by dissolving per- 
oxide of iron in hydrofluoric acid. As the acid becomes saturated, 
crystals are formed in small, white, square tables, which are sparingly 
soluble in water. 

Protosulphuret of Iron (Fe-j-S. 44.1) is prepared by 
heating equal parts of sulphur and iron-filings in a covered 
Hessian crucible; considerable heat is evolved, and a yel- 
lowish-gray substance is formed ; this is completely dissolved, 
if pure, by dilute sulphuric acid, yielding hydrosulphuric 
acid. It exists in nature, in the variegated copper pyrites, 
and forms a black precipitate, when hydrosulphate of ammo- 
nia is mixed with the sulphate of the protoxide of iron. 

Sesquisulphuret of Iron (2Fe-f- 3S. 104.3) is formed by the action of 
ihe hydrosulphuric acid on the hydrated peroxide of iron. 

, It has a yellowish-gray color, and dissolves in dilute sul- 
phuric and hydrochloric acids, with the formation of hydro- 
sulphuric acid and bisulphuret of iron. 

Bisulphuret of Iron. Fe-j-2S. 60.2. This is the iron 
pyrites of mineralogists, and occurs abundantly in cubes, or 
in some analogous form, of a yellow color, and metallic lus- 
tre ; sp. gr. 4.981 ; so hard as to strike fire with steel ; hence 
its name. 

It is dissolved by nitrohydrochloric acid, but by no other 
acid, except the nitric. By heat, it is converted into magnet- 
ic iron pyrites, if in close vessels, but exposed to the air, into 
the peroxide of iron. 

Magnetic Iron Pyrites. (5Fe + S) + (Fe+2S.) 280.7. 
This natural product appears to be composed of 5 equivs. 
of the protosulphuret and 1 of the bisulphuret. It may 
be formed as above. It is much more easily oxidized than 
the bisulphuret. 

Tetrasulphuret of Iron (4Fe + S. 128.1) and the Bisulphuret of Iron 
(2Fe + S. .72) may be formed by passing hydrogen gas, at a red heat, 
over the anhydrous sulphate of the protoxide of iron, to obtain the di 



Compounds of Iron. 25b 

eulphuret, and over the disulphate of the peroxide of ircra, for the tetra- 
sulphuret. 

Properties. They exist in a grayish-black powder, soluble 
in dilute sulphuric acid, with the evolution of hydrogen and 
hydrofluoric acid gases. 

Diphosphuret of Iron (2Fe-f-P. 71.7) is prepared by heating the 
phosphuret in a covered crucible, lined with charcoal. 

Properties. It is a fused, granular substance, which re- 
sembles iron in color and lustre, but is very brittle, and ren- 
ders iron brittle, when contained in it, as it sometimes is. 

Pcrphosphuret of Iron (3Fe -f-4P. 146.8) is obtained by the action of 
phosphuret of hydrogen on sulphuret of iron, and resembles the pre- 
ceding in most of its properties. 

Carburets of Iron. Carbon and iron unite in several pro- 
portions; only three seem worthy of notice — graphite, cast 
or pig iron, and steel. 

Graphite is known as a natural product, under the names 
of plumbago and black-lead. There is not more than 10 per 
cent, of iron, and often not 5. Used for pencils, crayons, 
crucibles, and for burnishing iron. * 

Cast Iron is a compound of carbon and iron, and is the 
product of melting the ores of iron'with charcoal. Its uses 
are well known. 

Steel is formed by filling a furnace with bars of the best 
malleable iron, with layers of charcoal between, and subject- 
ing them to strong heat away from the air; about 1.3 to 1.75 
per cent, of carbon combines with the iron. This is the 
substance used for the various purposes of the arts. It is 
much harder than iron, but more brittle, also less ductile and 
malleable, but more firm in its texture, and capable of a 
higher polish. By fusion it forms cast steel. 

Protoajantde of Iron (Fe -f- Cy. 54.39) is prepared by mixing in 
solution cyanide of potassium with sulphate of protoxide of iron; on 
exposure to the air, it passes to Prussian blue. 

Protosulphocyanide of Iron (Fe -\- CyS 2 . 86.59) is obtained by dis- 
lolving iron in hydrosulphocyanuric acid, and evaporating the pale 
green solution to dryness in vacuo. 

Scquisvlphoryanide of Iron (2Fe -f- 3CyS 2 . 231.77) is prepared by 
mixing the sulphocyanide of potassium with any salt of the peroxide 
of iron. It has a blood-red color, and is a very delicate test of the 
presence of iron. 



256 Metals —Zinc 



ZINC. Sjrab. Zn. Equiv. 32.3. Sp. gr. 7.00. 

Zinc has long been known in the East, India and China, 
but was first distinctly noticed in the sixteenth century, h) 
Paracelsus, under the name of zinetunj,. Henckel is the first 
who obtained the metal from calamine, in the year 1721 
Von Swab first obtained it by distillation in 1742; and Mar« 
graff published a process in the Berlin Memoirs in 1746. 

Natural History. Zinc, like most of the metals, is rarely 
found pure in nature, but is an abundant substance in com- 
bination with oxygen, carbon, and sulphur. 

Process. Commercial zinc, or spelter, is generally ob- 
tained from calamine, native carbonate of zinc, or from the 
native sulphuret, called by mineralogists zinc blende. This 
is oxidized by heating it in the open air, called roasting. It 
is then distilled ; that is, it is heated in a crucible open at 
the bottom and closed at the top, to which is affixed a tube, 
which .terminates just above a basin of water ; the gaseous 
products, with the vapor of zinc, pass through the tube, and 
the zinc is condensed. The first portions are impure, con- 
taining cadmium and arsenic, which give the brown blaze ; 
when the blue blaze is seen, the zinc is collected. It con- 
tains now some impurities, which are removed by a white 
heat in an earthen retort, to which a receiver full of water is 
adapted. 

Properties. This metal is bluish-white, with a strong 
metallic lustre and lamellated texture. It is a hard and brittle 
metal; but between the temperatures of 210° and 300° Fahr., 
it is malleable and ductile, and in this state is rolled out into 
plates; fuses at 773° Fahr., and when slowly cooled, crystal- 
lizes in four or six-sided prisms. It is easily pulverized 
when heated to a certain temperature below redness, and 
sublimes at a high temperature in close vessels, without 
change 

Uses. Zinc is used extensively in the arts, for the construction of 
voltaic instruments, and for covering buildings. It has been pro 
posed to use it for culinary vessels, water-pipes, and sheathing fo 
ships; but it is so easily oxidized and acted upon by the weakes.' 
acids, that it is unfit for these uses. 



Compounds of Zinc. 257 

Compounds of Zinc. 

Protoxide of Zinc. Zn -|- O. 40.3. This is the only known 
oxide of zinc, formerly called floioers of zinc, nihil album, 
and philosopher's wool. 

Process, It is obtained by the combustion of zinc in the 
open air, in oxygen gas, or by heating the carbonate to red- 
ness. It is found native in Franklin, New Jersey. 

Exp. Melt zinc in a covered crucible, and when it is at a white 
heat, remove the cover; it will burst out into a white flame, forming 
the oxide. 

The Hydratcd Oxide of Zinc may be obtained by uniting 
a rod of iron and zinc, and placing them in caustic ammonia, 
in a close vessel. 

Properties. At common temperatures it is white, but as- 
sumes a yellow color when heated to redness ; insoluble in 
water, and is a strong salifiable base. 

The oxide is precipitated from its solutions, as a white hy- 
drate, by pure potassa and ammonia, and as a carbonate 
by alkaline carbonates. The oxide is sometimes substituted 
for white lead for paint; it is more durable, but not so white. 

Berzelius describes a suboxide, and Thenard a binoxide, 
but they are doubtful substances^ 

Chloride of Zinc (Zn -f- CI. 67.72) is formed by burning zinc-filings 
in chlorine. It is colorless, fusible a little above 212°, and has so soft 
a consistency at common temperatures, as to be called butter of zinc. 

Iodide of Zinc (Zn -f- I. 158.6) is prepared by digesting iodine in 
water with zinc-tiiings. 

Bromide of Zinc (Zn-j-Br. 110.7) is formed in a similar mannez 
with the preceding. 

Fluoride of Zinc (Zn -j- F. 50.08) is prepared by the action of hydro- 
fluoric acid on the oxide of zinc. It exists as a white solid, 

Sulphuret of Zinc (Zn-f-S. 48.4) is a native product, 
known by the name of zinc blende. It may be formed by 
heating sulphur with the oxide; it crystallizes in dodeca- 
hedrons; lamellated structure ,. adamantine lustre; color red, 
yellow, brown, or black. Cyanide of Zinc. ZnCy. 58.69. 

C1DMIUM. Symb. Cd. Equiv. 55.8. Sp. gr. 8.604. 

History. Cadmium was discovered in 1817, by Stromeyer, 
of Gottingen, in an oxide of zinc which had been prepared 



258 Metals. — Cadmium. 

for medical use. Dr. Clark detected it in the zinc ores of 
Derbyshire, and in the common zinc of commerce, and 
Mr. Herapath found it in considerable quantities in the zinc 
works near Bristol, England. 

Process. The following is the process of Stromeyer ■ 
The ore of cadmium is dissolved in hydrochloric or sulphuric 
acid in excess. The sulphuret of cadmium is precipitated 
by hydrosulphuric acid. Nitric acid decomposes this, and 
forms a nitrate, which is evaporated to dryness. To a solu- 
tion of this in water, an excess of carbonate of ammonia is 
added, and the white carbonate of the oxide of cadmium is 
precipitated, which, when subjected to a red heat, yields a 
pure oxide. The metallic cadmium is obtained from the ox- 
ide, by heating it with charcoal. 

Properties. Cadmium resembles tin in its color and lus- 
tre, but is harder and more tenacious ; very ductile and 
malleable ; melts at about the same temperature as tin, and 
is nearly as volatile as mercury. Heated in the open air, it 
absorbs oxygen, and is converted into the 

Oxide of Cadmium, (Cd-f-O. 63.8,) which is the only 
known oxide; is a strong alkaline base, forming neutral salts 
with acids; insoluble in water; fixed in the fire; and pre- 
cipitated by all the alkaline carbonates, and by pure ammonia 
and potassa, 

Chloride of Cadmium. Cd-j-Cl. 91.22. This compound 
is formed by dissolving oxide of cadmium in hydrochloric 
acid. By concentration, the chloride crystallizes in four- 
sided rectangular prisms, which lose their water of crystal- 
lization by heat, and even in dry air; fused below redness, 
and sublimes at a high temperature. 

Iodide of Cadmium (Cd-}-I. 182.1) is formed in the same way as 
the iodide of zinc ; soluble in water and alcohol, and crystallizes in 
large, colorless, transparent, hexagonal tables, which do not change in 
the air, and have a pearly lustre. By heat they lose water, and then 
fuse. 

Sulphuret of Cadmium (Cd -\- S. 71.9) occurs in nature in 
zinc blende, and is prepared by the action of hydrosulphuric 
acid on the salts of cadmium. It has a yellowish-orange 
color, and may be distinguished from the sulphuret of arsenic 
by being insoluble in pure potassa, and by sustaining a white 
heat without subliming. 



Itn. 259 

Phosphuret of Cadmium is a gray compound, very brittle and 
Fusible 



27JV. Symb. Sn. Equiv. 58.9. Sp. gr. 7.2. 

Tin was known to the ancients, in the time of Moses ; 
and was obtained, chiefly from Cornwall, England, and Spain, 
at a very early period, by the Phoenicians. 

Process. The tin of commerce is obtained from the 
native oxide by heat and charcoal, and in the form of block 
and grain tin. 

Stream Tin is the native oxide of Cornwall, which is 
found in rounded pebbles, occasioned by the action of water. 
Tin is seldom perfectly pure, containing a little copper, iron, 
and arsenic. That from Malacca is the purest. 

Tin Foil is often an alloy of tin and lead. Block tin is 
less pure than grain tin. 

Properties. Tin has a color and lustre resembling silver. 
It is very malleable. Tin foil does not exceed j^q- of an 
inch in thickness, but its ductility and tenacity are inferior to 
many of the metals. When bent backward and forward, a 
crackling noise is produced, by which it may be readily dis- 
tinguished from lead, zinc, etc. It fuses at. 240° Fahr. When 
heated to whiteness, it takes fite. If a drop of the fused tin 
fall upon a board, it will divide into several globules, and 
burn with a beautiful white light. The brilliancy of its sur- 
face tarnishes slowly when exposed to the air at common 
temperatures, but oxidizes at a high temperature. 

Compounds of Tin. 

Protoxide of Tin (Sn + O. 66.9. sp. gr. 6.666) is formed 
by fusing tin for some time in an open vessel, or it may be 
precipitated, as a hydrated oxide, from a solution of chloride 
of tin, by an alkaline carbonate. 

Properties. It is a gray powder, permanent in the air, unl- 
ess touched by a red-hot body, when it takes fire, and is con- 
verted into the peroxide. It is dissolved in the strong acids, 
and the pure, fixed alkalies. Its salts readily absorb oxygen 
from the air and other compounds; hence it throws down 



260 Metals. — Tin. 

mercury, silver, and platinum, from their salts. With gold 
it causes the purple precipitate of Cassius ; by this charac- 
ter it is readily distinguished. It is precipitated from its 
solutions by hydrosulphuric acid as a black protosulphuret. 

Sesquioxide of Tin (2Sn -f- 30. 139.8) is prepared by. mixing recent y- 
precipitated and moist hydrated peroxide of iron with a solution of 
protochloride of tin. The sesquioxide is precipitated in a slimy, gray 
matter, of a yellowish tint, from oxide of iron ; distinguished from the 
protoxide by being soluble in ammonia. 

Binoxide of Tin (Sn -f-20. 74.9) is prepared by the action 
of nitric acid on metallic tin. The concentrated acid doeg 
not act on the tin, but, on the addition of water, violent effer- 
vescence takes place, and a white powder — the hydrated bi- 
noxide of tin — is formed. The water is expelled by heat, and 
the pure binoxide, of a straw-yellow color, results. The hy- 
drated oxide may also be precipitated from the protochloride 
by potassa, ammonia, or the alkaline carbonates; but the 
properties differ from that formed in the other way, the latter 
being dissolved in the strong acids, while the former is not. 
It acts the part of a feeble acid, uniting with the pure alka- 
lies, and forming a class of compounds — the stannates. 

Binoxide of tin is recognized by its being precipitated 
from its solutions by hydrochloric acids as a bulky hydrate, 
and by any of the alkalies or alkaline carbonates. When 
melted with glass, it forms a white enamel. 

Protochloride of Tin (Sn-f-Cl. 94.32) is obtained by distilling equal 
weights of tin and bichloride of mercury. It is a gray solid, of resin- 
ous lustre ; fuses below redness, and sublimes at a high temperature ; 
crystallizes in small, white needles. A solution of the protochloride 
may be prepared for deoxidizing purposes, by heating granulated tin 
in strong hydrochloric acid, as long as hydrogen gas is evolved. 

Bichloride of Tin (Sn~f-2C1. 129.74) is formed by distilling 8 parts 
of granulated tin with 24 of bichloride of mercury, or by heating the 
protochloride -in chlorine gas. 

Properties. It is a colorless liquid, very volatile, yielding 
white fumes in an open vessel ; hence formerly called the 
fuming liquor of Libavius ; boils at 248° ; sp. gr. of its 
vapor, 9.1997; mixed with ^ of its weight of water, it forms 
a solid hydrate, but dissolves in a larger quantity of water. 

Uses. The solution called yermuriate of tin is used in dyeing, and 
is prepared by dissolving tin in nitrohydrochloric acid. 

Protiodide of Tin (Sn + L 185.2) is prepared by heating granulated 
tin with 2£ times its weight of iodine. It is a brownish-red substance 
very fusible, volatile, and soluble. 

Biniodide of Tin (Sn-f-2I. 311.5) is prepared by dissolving the hy 



Cobalt. 261 

drate of the peroxide, precipitated by alkalies, from the bichloride, in 
hydriodic acid. It forms yellow crystals of a silky lustre. 

Protosulphuret of Tin (Sn-f-S. 75) is prepared by pouring melted 
tin upon its own weight of sulphur, and stirring rapidly with a stick. 
It has a bluish-gray, or nearly black color, and metallic lustre ; fuses 
at red heat, and has a lamellated texture when cool. 

Scsquisulphurct of Tin (2 Sn-f-3S. 166.1) is obtained by heating to 
low redness the protosulphuret with £ of its weight of sulphur. It is 
a deep grayish-yellow compound. 

Bisulphuret of Tin. Sn-f-2S. 91.1. This compound was formerly 
called Mosaic gold, and may be prepared by heating a mixture of 2 
parts of peroxide of tin, 2 of sulphur, and 1 part of hydrochlorate 
of ammonia, in a glass or earthen retort, to a low red heat, till sulphur- 
ous acid ceases to be evolved. 

Properties. It occurs in crystalline scales, of a golden- 
yellow color, and metallic lustre ; soluble in pure potassa, 
and its only solvent among the acids is the nitrohydrochlo- 
ric acid. It is obtained, as a hydrate, by the action of hy- 
drosulphuric acid, and the bichloride of tin, in solution. 

Terphosphuret of Tin (Sn-f-3P. 106) is formed, according to Rose, 
by the action of phosphuret of hydrogen on a solution of protochlo 
ride of tin. It oxidizes rapidly in the air. 



COBALT. Symb. Co. Equiv. 20.5. Sp. gr. 7.834. 

Cobalt was discovered by Brandt, and derives its name, 
Kobold, an evil spirit, from the belief of the German miners 
that its presence was unfavorable to that of valuable metals. 

Natural History. It exists in nature, generally, in com- 
bination with arsenic. It is also a constant ingredient in 
meteoric iron, and is found combined with sulphur and other 
combustibles. 

Process. It may be obtained from the oxide, by heating 
it in connection with charcoal, and then passing over it a 
stream of hydrogen gas, to combine with the oxygen. 

Properties. Cobalt is a brittle solid, of a reddish-gray 
color, and weak metallic lustre; fuses at 130° Wedgwood, 
and crystallizes when slowly cooled. It is attracted by the 
magnet, and is susceptible of being rendered permanently 
magnetic ; absorbs oxygen when heated in open vessels. It 
is also oxidizec by nitric acid, and decomposes water at a 
red heat. 



262 Metals. — Cobalt 



Compounds of Cobalt. 

Protoxide of Cobalt (Co-|-0. 37.5) is obtained by do 
composing the carbonate, by heat, in a vessel from which the 
air is excluded. 

Properties. It has an ash-gray color, and is the base of 
all the salts of the metal, most of which are a pink-blue 
When heated, it absorbs oxygen, and is converted into the 
peroxide. It is distinguished by giving a blue tint to borax 
when melted with it. 

Zaffre is an impure oxide of cobalt, obtained by heating 
the arseniuret in a reverberatory furnace. When this sub- 
stance is heated with sand and potassa, a beautiful blue- 
colored glass is formed, known by the name of smalt, and 
used in the arts for communicating the blue color to glass, 
porcelain, and earthen-ware. 

The protoxide is easily precipitated from its salts by alka- 
lies ; the precipitates are of a blue or pale pink color ; dis- 
solved in excess of alkali. 

I- Oxide of Cobalt (3Co-j-40. 120.5) is probably a compound of the 
peroxide and the protoxide. 

Peroxide of Cobalt (2Co -|- 3D. 83) is obtained as a black 
hydrate with 2 equivs. of water, when chloride of cobalt is 
decomposed by chloride of lime. The water is driven off 
by exposure to a heat of 600° or 700°. It combines with 
none of the acids, and, when strongly heated, is decomposed, 
and resolved into the protoxide and oxygen. 

Chloride of Cobalt (Co + Cl. 64.92) is obtained by dis- 
solving metallic cobalt, or either of its oxides, in hydrochlo- 
ric acid. The solution is of a pink color, and yields, on 
evaporation, small crystals of the same color. When -these 
crystals are deprived of their water of crystallization, they 
assume a blue color — a property on which is founded its 
use as a sympathetic ink. 

Exp. Write on paper with a dilute solution of the chloride, and 
expose it to a gentle heat; it becomes blue. This solfttion is called 
Hill of s sympathetic ink, and is described by some chemists as a mu- 
riaie of cobalt ; but Turner thinks it a chloride, analogous to several 
other compounds generally described as muriates of the metals. 

Exp. Draw the branches of a tree with India ink, and put on th« 
foliage with the chloride of cobalt. When cold, the foliage does not 
appear, but shows itself on the application of heat. A landscape may 



Compounds of Nickel. 263 

oe represented, in this manner, as wintry or vernal, according as the 
heat is increased or diminished. 

Sulphurets of Cobalt. Cobalt unites with sulphur in three 
proportions. 

The Protosulphuret (Co-f-S- 45.6) is formed by throwing fragments 
of sulphur on red-hot cobalt; has a gray color, a metallic lustre, and 
crystalline texture. 

The Scsquisulphuret of Cobalt (2Co-f*3S. 107.3) is formed by pass- 
ing a current of hydrosulphuric acid gas over the oxysidphuret, at a 
red heat. 

Thr. Bisulphurel (Co-f-2S. 61.7) is prepared by heating below red- 
ness, in a glass tube, 2 parts of the carbonate of the oxide of cobalt, 
intimately mixed with 3 of sulphur. 

Subphosphuret of Cobalt (3Co + 2P. 119.9) is obtained by the action 
of phosphureted hydrogen on chloride of cobalt. It is a pulverulent 
gray solid. 

MCKEL. Symb. Ni. Equiv. 29.5. Sp. gr. 8.2579 

Nickel was discovered by Cronstedt in 1751, in the kup- 
fer nickel (copper nickel) of Westphalia. The term nickel 
was applied to the ore because it looked like copper, but did 
not yield it. It exists also in meteoric iron. 

Process. Nickel may be extracted from the ore, — which 
is an arseniuret of nickel, containing small quantities of 
sulphur, copper, cobalt, and iron, — or from speiss ; also an 
arseniuret which is obtained in forming smalt from the 
roasted ores of cobalt. This metal is obtained by heating 
the oxalate or the oxide with charcoal in close vessels.* 

Properties. Color white, intermediate between tin and 
silver; strong metallic lustre; ductile and malleable; at- 
tracted by the magnet, and, like iron and cobalt, may be 
rendered permanently magnetic ; a little less infusible than 
iron ; oxidized at a red heat, and by nitric acid. 

Compounds of Nickel. 

Protoxide of Nickel (Ni-f-O. 37.5) is formed by heating 
the carbonate, oxalate, or nitrate, to redness, to drive off the 
acid. 

* For processes, see Turner's Elements, p. 351 . 



264 Metals. — • Arsenic. 

Properties Color at first an ash-gray, but, when exposed 
to a white heat, it is of a dull olive-green. This is the 
strong alkaline base of the metal, and nearly all the salts 
have a green tint. Pure alkalies precipitate this oxide from 
its salts, as a hydrate of a pale green color. The alkaline 
carbonates and hydrosulphurets also precipitate it from its 
salts, the former as a carbonate, the latter as a sulphuret of a 
black color. 

Sesguiozide of Nickel (2Ni-f-30. 83) is formed by transmitting 
chlorine through water, in which the hydrate of the protoxide is sus- 
pended. It has a black color, does not unite with acids, and is decom- 
posed at a red heat. 

Chloride of Nickel (Ni-j-Cl. 64.92) is formed by the action of hydro- 
chloric acid upon metallic nickel, or one of its oxides; an emerald- 
green solution is formed, and, on evaporation, yields crystals of the 
same tint, which deliquesce in moist air, and effloresce if the air is dry. 

Protosulphuret of Nickel (Ni-f-S. 45.6) is formed by a similar pro- 
cess with the protosulphuret of cobalt ; occurs native in acicular 
crystals — the haarkies of the Germans. When dry, it is of a grayish- 
yellow color, while the precipitates are dark brown ; soluble in nitric 
or nitrohydrochloric acid. 

Disulphuret of Nickel (2Ni-j-S. 75.1) is obtained by passing hydro- 
gen gas over the sulphate of nickel at a red heat ; color light yellow, 
and is more fusible than the preceding. 

Subphosphuret of Nickel (3Ni-f 2P. 119.9) is obtained by the action 
of hydrogen on subphosphate of oxide of nickel. Color black, solu- 
ble in nitric acid, and burns with a flame under the blowpipe. 

Cyanide of Nickel (JSi-j-Cy. 55.89) is obtained by mixing in solu- 
tion a salt of nickel with cyanide of potassium. A precipitate ia 
formed, of a pale, apple-green color, which becomes tinged with yellow 
on drying. 



Sect. 2. Metals which do not decompose Water ai 
any Temperature, and the Oxides of which are not 
reduced to the metallic state by the sole action 
of Heat. 

ARSENIC. Symb. As. Equiv. 37.7.* Sp. gr. 5.8853. 

Arsenic was first discovered by Dioscorides, who called 
it Sandarac; but its properties were first investigated by 
Brandt, in 1733. 

Natural History. It exists in nature, in small quantities, 
rarely in a metallic state. It is generally found in com 
* By sonw chemists the equiv. for arsenic is 75.34i 



Compounds of Arsenic. 265 

oination with cobalt and iron, and occasionally with other 
metals. 

Process. Metallic arsenic is obtained by roasting the ores 
in a reverberatory furnace; as the arsenic is expelled by heat, 
it combines with oxygen, and condenses into thick cakes on 
the chimney. These cakes are purified by a second sublima- 
tion, and constitute the white oxide of arsenic — a virulent 
poison. This substance is then mixed with twice its weight 
of black flux * exposed with charcoal to a red heat in a Hes- 
sian crucible; and the metal is sublimed and collected in an 
empty crucible, which is placed over the other, and kept cooi 
for the purpose of condensation. 

Properties. Arsenic is a very brittle metal, of a steel-gray 
color, high metallic lustre, and of a crystalline structure. 
When heated to 356°, it sublimes without fusion, and may be 
collected in close vessels without change ; but, when thrown 
on a red-hot iron, it burns with a blue flame and white 
smoke, giving off a strong odor of garlic — a property which 
belongs to no other metal, unless it be zinc; when thus 
heated in the open air, it is converted into the white oxide 
of arsenic. Exposed at common temperatures of the air, it 
oxidizes slowly, forming the substance called fly-powder^ 
which is a mixture of the oxide and the metal. 

Arsenic detonates with some of the salts, and decomposes 

them. 

Exp. Take 3 parts of chlorate of potassa, and 1 of arsenic, finely 
powdered, and cautiously mixed together. 

1. Place a small quantity on an anvil, and strike it with a hammer; 
the arsenic will instantly combine with the salt, producing an explosion 
with flame. 

2. Set it on fire, and it will burn rapidly. 

3. Throw it into concentrated sulphuric acid, and a bright flash of 
li b 'ht will be perceived at the moment of contact. 

Uses. Arsenic is used in the arts. It renders glass 

wnite. 

Compounds of Arsenic. 

Arsenious acid, (2As -|- 30. 99.4,) commonly called white 
arsenic and white oxide of arsenic, may be formed by the 

* Prepared by detonating, in a crucible, T part of nitre with 3 of 
the crystals of tartar. 12 



266 Metals . — A rsenic. 

combustion of the metal ; but the white arsenic of commerce 
is obtained from the arseniurets of cobalt, by sublimation. 

Properties. Arsenious acid is white, semitransparent, 
and, when first formed, of a vitreous lustre and concboidal 
fracture. Its acid taste is owing to the inflammation which 
it produces ; it has a faint impression of sweetness. Its 
sp. gr. is 3 7 ; has two crystalline forms, but is usually found 
in six-sided scales, derived from a rhombic prism ; soluble. 
in water. 

It is one of tJie most virulent poisons known ; and, as it is 
sometimes accidentally or intentionally taken, it is a frequent 
cause of death, and a subject of judicial investigation. Hence 
the importance of pointing out the most effectual modes of 
detecting its presence. 

Tests. The most valuable are the ammoniaco-nitrate of 
silver, ammoniaco-sulphate of copper, hydrosulphuric acid, 
and hydrogen gas. 

1. Obtain as larcre a quantity of the liquid from the stom- 
ach as possible. This, with parts of the stomach, should be 
put into pure water, filtered and evaporated, so as to obtain 
a concentrated solution; add to this, ammoniacal nitrate of 
silver,* and if arsenic is present, a yellow — arseniate of sil- 
ver — will be thrown down. 

2. Add to the suspected liquid ammoniacal sulphate of 
copper,f and a green precipitate will be formed, called 
Scheele's green. 

3. Pass into the liquid, hydrosulphuric acid, and if arseni- 
ous acid is present, "orpiment, or the sesquisulphuret of 
arsenic will be formed, giving to the liquor a yellow, turbid 
appearance. This sulphuret should then be dried, mixed 
with black flux, carefully introduced into a glass tube, and 
heated by a spirit lamp; the sulphuret will be decomposed, 
and metallic arsenic appear on the cool parts of the tube. 
This is a very satisfactory test ; but if, on heating the sub- 

* Prepared by dropping into a strong solution of nitrate of silver 
ammonia, till the oxide of silver, first precipitated, is nearly all dis- 
solved. 

t Prepared in the same way with the preceding, by using the sul 
phate of copper, instead of the nitrate of silver 



Compounds of Arsenic. 267 

Btance thus deposited, it rises up in white fumes, with an 
alliaceous odor, and is deposited in white, octohedral crystals, 
we may be sure that arsenic is present. 

4. Introduce a quantity of the suspected liquid into a 
Florence flask, having a jet pipe and a stop-cock attached, 
with zinc and sulphuric acid; the water will be decomposed, 
and the nascent hydrogen, in passing through the water con- 
taining arsenious acid, will form arseniureted hydrogen; 
and on burning the gas, as it issues from the jet, metallic 
arsenic will be deposited on a plate of glass or porcelain, 
held over the flame. 

Any one of these tests, however, should not be depended 
upon in a case where the life of a fellow-being is at stake, as 
other metals, such as antimony, will sometimes present a 
similar appearance; but if the suspected substance be tested 
by each of the four ways mentioned, there can be no doubt 
but that it contains arsenious acid. 

Its action upon animals, whether taken into the stomach, or applied 
to wounds, is attended by pain and vomiting; and if life be prolonged 
beyond twenty-four hours, diarrhoea, a sensation of heat, and extreme ~ 
pain in the stomach and intestines, succeed, pulse feeble, countenance 
anxious, skin livid, often attended by eruptions. 

The best antidote is pcrhydrate of iron, with a small quantity of am- 
monia. In case3 rapidly fatal, extreme faintness, cold sweats, attended 
with plight convulsions, are experienced. (See Christison on Poisons.) 

Arsenic has the property of preserving from decay the bodies of 
those poisoned with it. The stomach and intestines have thus been 
found entire two years and a half after death. 

Arsenic Acid (2As-|-50. 115.4) is formed by dissolving 
arsenious acid in concentrated nitric, mixed with a small 
quantity of hydrochloric acid, distilling in a glass vessel until 
it acquires the consistency of sirup, and then heating nearly 
to redness, in a platinum crucible, to expel the nitric acid. 

Properties. It has a sour, metallic taste, reddens the vege- 
table blue colors, and combines with alkalies, forming arse- 
nates. It is decomposed by hydrosulphuric acid. This 
acid is also an active poison. 

Protochloride of Arsenic (AsCl. 73.12) is prepared by heating in a 
retort, to nearly '212°, arsenious acid, with ten times its weight of con- 
centrated sulphuric acid, and throwing them in fragments of common 
salt. 

Sesquichloride of Arsenic (As 2 Cl 3 . 131.66) is formed by the sponta- 
neous combustion of powdered arsenic in chlorine gaa. It is a color 



268 Metals. — Chromium. 

less, volatile liquid, giving off fumes, on exposure to the air; hence 
called fuming liquor of arsenic. 

Periodide of Arsenic (2As-f-51. 706.9) is formed by gently heating 
arsenic with iodine. It is a deep red compound, decomposed by 
water. 

Protohyduret of Jlrsenic (As-f-H. 38.7) is prepared by the action of 
water on an alloy of arsenic and potassium. 

Sesquibromide of Arsenic. 2As-f-3Br. 310.6. When arsenic and 
bromine are brought into contact, they instantly unite with vivid evo- 
lution of light and heat. 

Hyduret of Arsenic. 2As-{~3H. 78.4. This gaa 
was discovered by Scheele. It is generally made by digest- 
ing an alloy of tin and arsenic in hydrochloric acid. It is 
colorless; nas a fetid odor resembling garlic; sp. gr. 2.695; 
extinguishes burning bodies, but burns with a blue flame. 
It is poisonous in a high degree, having proved fatal to M. 
Gehlen. It is decomposed by chlorine, iodine, caloric, and 
even atmospheric air ; it forms with oxygen an explosive 
mixture. 

Protosulphurei of Arsenic. As-f-S. 53.8. This substance 
exists in the mineral kingdom, and is called realgar. It 
may be formed by heating arsenious acid with half its weight 
of sulphur, until the mixture is perfectly fused. It is crys- 
talline, transparent, and of a ruby-red color. 

Sesquisulphuret of Arsenic. 2As -J- 3S. 123.7. This in 
the native state is called orpiment. 

Process. It may be formed by fusing arsenious acid and sulphur, 
but it is purer, if obtained by passing hydrosulphuric acid gas through 
a solution of^arsenious acid. 

Properties. This substance has a rich, yellow color, and 
is employed as a pigment. It is the coloring principle in 
the paint called king's yellow. 

Persulphuret of Arsenic (2As-|-5S. 155.9) is formed by passing 
hydrosulphuric acid through a moderately strong solution of arsenic 
acid. It resembles orpiment in color. The sulphurets of arsenic are 
■>Qisonous. 



CHROMIUM. Symb. Cr. Equiv. 28. Sp. gr. 5.9. 

CJiromium* was discovered in 1797, by Vauquelin, in a 
beautiful red mineral, the native chromate of lead. It exists 



* X^aJjua, color, from its remarkable tendency to form colored com 
pounds. 



Compounds of Chromium. 269 

also in chromate of iron, a native mineral found aoundantly 
in Europe, and also in this country. 

Process. This metal has been obtained only in small 
quantities, owing to its affinity for oxygen. The oxide may 
be deprived of its oxygen, by heating it with charcoal in a 
smith's forge.' 

Properties. A brittle metal, of a grayish-white color, and 
very infusible. It is oxidized by heating it with nitre, and 
converted into chromic acid. 

Compounds of Chromium. 

Sesquioxide of Chromium. 2Cr -j- 30. 80. Exists native 

in the emerald. 

Process. It is prepared by dissolving chromate of potassa in water, 
and mixing it with a solution of nitrate of mercury, when a yellow- 
colored precipitate — the chromate of mercury — is formed. When this 
salt is heated to redness in an earthen crucible, the mercury is driven 
off, and the chromic acid is resolved into oxygen, and oxide of chro- 
mium. 

Properties. Oxide of chromium is of a green color, very 
infusible, insoluble in water, and after being strongly heated, 
resists the action of the most powerful acids ; heated with 
nitre, it is converted into chromic acid. Fused with borax 
or vitreous substances, it communicates to them a beautiful 
green color. Hence its utility in the arts. It unites with 
acids, and forms green-colored salts. 

Chromic Acid (Cr-|-30. Equiv. 52) may be obtained 

from the native chromate of iron. 

Process. It is best prepared by transmitting the gaseous fluoride 
of chromium into water contained in a vessel of silver or platinum; 
when, by mutual decomposition of the gas and the water, hydrofluoric 
and chromic acids are generated. — T. 

Properties. This acid is black while warm, and dark red 
when cold. When dry, according to Hayes, it is yellowish- 
brown, very soluble in water, rendering it red and yellow. 
When a heated concentrated solution cools, it deposits red 
crystals, very deliquescent. The solution has an acid, astrin- 
gent taste, and bleaches litmus paper. It destroys most vege- 
table and animal coloring matters. Hence its use in calico- 
printing. It is characterized by its color, and by forming 
colored salts with alkaline bases. 



270 Metals. — Vanadium. 

Sesqtrichloride of Chromium (2Cr-f-3Cl. 1R2.26) may be prepared 
by transmitting dry chlorine gas over a mixture of oxide of chromiuns 
and charcoal, heated to redness in a porcelain tube ; when the sesqui- 
chloride gradually collects as a crystalline sublimate of a peach-purph 
color. — T. 

Tcrchleride of Chromium (Cr-f-3Cl. 134.26) is formed by the actior 
of fuming sulphuric acid on a mixture of chromate of lead and chlcrid< 
of sodium. 

Oxychloride of Chromium. CrCl 3 -j-2Cr0 3 . 238.26. 

Sesquifluoride of Chromium (2Cr -f- 3F. 112.04) is formed by dissolv 
jng the oxide in hydrofluoric acid, v and evaporating to dryness. 

Terfluoride of Chromium. Cr -f 3F. 28 -f 56.04 = 84.04. 

Sesquisulpkuret of Chromium (2Cr 4-3S. 104.3) may be obtained by 
heating in close vessels a mixture of sulphur and the hydrated oxide. 
It is of a dark-gray color, acquiring a metallic lustre by friction. 

Protophosphuret of Chromium (Cr-f-P or CrP. 43.7) is prepared by 
passing phosphureted hydrogen gas over the sesquichloride of chro- 
mium at a red heat ; a black compound, burning before the blowpipe, 
with a flame of phosphorus. 



VANADIUM. Symb. V. Equiv. 68.5. 

Vanadium was_ discovered by Sefstrom, in 1830. It de- 
rives its name from Vanadis, a Scandinavian deity. 

Natural History. It exists in the iron ore of Taberg, 
Sweden, and is found in great abundance in the slag formed 
by converting the cast iron of Taberg into malleable iron. 
It was also found by Johnson, at Wanlock-Head, Scotland, 
where it occurs as a vanadiate of lead. 

Process. It has been obtained in various ways — by heat- 
ing vanadic acid with potassium, and by the decomposition 
of the chloride of vanadium.* 

Properties. When obtained by means of potassium, it is 
a brittle, black substance ; but when prepared by decompo- 
sing the chloride, it is white, resembling silver, of a strong 
metallic lustre. It is not oxidized by air or water ; boiling 
sulphuric, hydrochloric, and hydrofluoric acids do not affect 
it, but it is dissolved by nitric and nitrohydrochloric acids 
and the solution has a fine, dark blue color. 



For processes, see Turner's Elements. 



Compounds of Vanadium — Molybdenum. 271 

Compounds of Vanadium. 

Protoxide of Vanadium (V -j-O. 76.5) may be obtained by heating 
ranadic acid with charcoal or hydrogen gas. It is a dark brown, or 
black, substance, soluble in nitric acid. 

Binoxide of Vanadium (V-j-20. 84.5) may be prepared by heating 
to full redness 10 parts of the protoxide, with 12 of vanadic acid, in a 
vessel filled with carbonic acid. It is black, very infusible, and insolu- 
ble in water. Its salts have a blue color. It acts the part of an acid 
oy uniting with alkaline bases. 

Vanadic A cid (V -{- 30. 92.5) is tasteless, insoluble in 
alcohol, and very slightly soluble in water. It is easily de- 
composed by heating it with combustible matter, and in solu- 
tion by all deoxidizing agents. It unites with bases often in 
two or more proportions ; most of its neutral salts are yellow. 
It is distinguished from all other acids, except the chromic, 
by its color, and from this acid by the action of deoxidizing 
substances, which give a blue solution with the former, and 
green with the latter.* 



MOLYBDENUM. Symb. Mo. Equiv. 47.7. Sp. gr. 8.615 

Molybdenum was discovered in 1775. 

Process. It was obtained from the native sulphuret, by 
digesting it in nitrohydrochloric acid, and heating the mo- 
lybdic acid, thus formed, in connection with charcoal. 

Properties. It is a brittle metal, of a white color, and 
very infusible. Its properties are imperfectly known. 

Protoxide of Molybdenum (Mo-J-O. 55.7) is obtained by 
precipitating the hydrochloric solution of molybdic acid by 
zinc, when a brown hydrate is formed, giving dark colored 
solutions with the acids. 

Binoxide of Molybdenum (Mo -f- O. 63.7) is prepared by putting a 
mixture of molybdate of soda and sal-ammoniac, in fine powder, in a 
red-hot crucible, instantly covering it, and continuing the heat until 



* The bichloride of vanadium, (VC1 2 . 68.5 -f- 70.34 == 139.34 ;) the 
lerchhridr of vanadium, (VCl*. 68.5 + 1 06.26 = 174.76 ;) the bibromide 
of vanadium, (VBr 2 . tie.5 -j- 156.8 = 225.3 ;) the bisulphuret of vana- 
dium, (VS*. 68.5 + 32.2=100.7;) the tersidphuret, (VS 3 . 68.5 + 48.3 
e= 116.8,) are unimportant compounds, for a description of which, see 
Turner s Elements, p. 365. 



272 Metals. — Tungsten. 

vapors of sal-ammoniac cease to arise. This is a deep brown anhydront 
powder, insoluble in acids. 

Molybdic Acid (Mo + 30, or MO 3 71.7) may be obtained 
by roasting the native sulphuret in an open, crucible, kept at 
a low red heat, and stirred until sulphurous acid ceases to 
escape. The yellow powder, thus formed, is treated with 
ammonia ; the filtered solution evaporated, again disso ved 
in water and ammonia, and crystallized ; the ammonia is 
then expelled by gentle heat. 

It is a white powder ; sp. gr. 34.9 ; fuses at a red heat into 
a yellow liquid ; slightly soluble in water.* 



TUNGSTEN. Symb. W. Equiv. 94.8. Sp. gr. 17.5 

Tungsten is found native in the mineral wolfram. 

Process. It is obtained by exposing a mixture of tungstic 
acid and charcoal to a strong heat. 

Properties. It is a very hard, brittle metal, resembling 
iron in color, and, by the action of heat and air, converted 
into tungstic acid. 

Compounds of Tungsten. 

Binoxide of Tungsten (W -{-20. 110.8) is prepared by 
the action of hydrogen gas on tungstic acid, at a low red 
heat. It has a brown color, resembling copper wherj 
polished. 

Tungstic Add (W + 30. 118.8) may be obtained by 
heating the binoxide to redness in open vessels. It is of a 
yellow color, insoluble in water, and has no action on litmus 
paper. 

Bichloride of Tungsten (W + 2C1. 165.64) is formed by 
heating tungsten in chlorine gas.f 



* For the preparation of the protochloride of molybdenum, (Mod 
83.12:) the bichloride of molybdenum, (Mod*. 118.54;) the terchlorias 
of molybdenum, (MoCl 3 . 153 96';) the tersulphuret of molybdenum, 
(MoS 3 06,) and the persulphuret of molybdenum, (MoS 4 . 11.2.1,) the 
student is referred to Turner's Elements, p 369. 

t For a description of the ter chloride of tungsten, (W CI 3 . 201.6 ;) bi' 
sulphuret of tungsten, (WS 2 . 126;) and tersulphuret of tungsten, (WS 1 
143.1,) see Turner's Chemistry. 



Columbium — Antimony. 273 



COLUMBIUM. Symb. Ta. Equiv. 185. 

Columbium was discovered in 1801, by Hatchett, in a 
black mineral in the British Museum, which had been sent 
by Governor Winthrop to Sir Hans Sloane, from Haddam, in 
Connecticut. 1 * 

Process. It is obtained by heating potassium with the 
double fluoride of potassium and columbium. 

Properties. Obtained in this way, it is a black powder, 
and a non-conductor of electricity, but a perfect conductor 
in a more dense state. It acquires a metallic lustre by pres- 
sure ; of an iron-gray color ; fuses at a higher temperature 
than glass ; heated in the open air, it takes fire, and is con- 
verted into columbic acid. It is easily dissolved in nitro- 
liydrofluoric acid. 

Compounds of Columbium. 

Binoxide of Columbium (Ta-f- 20. 201) may be formed by exposing 
columbic acid in a crucible, lined with charcoal, and luted to exclude 
the air, for an hour and a half, to an intense heat. When reduced to 
powder, it is a dark brown substance, not acted upon by acids, but con 
rerted into columbic acid by fusion with potassa or nitre. 

Columbic Acid (Ta -\- SO. 209) is formed from the native columbates, 
Dy fusing the ores with three or four times their weight of carbonate of 
potassa, and precipitating the white hydrate by acids. 

Properties. Hydrated columbic acid is tasteless, insolu- 
ble in water, and communicates a red tinge to moistened lit- 
mus paper ; heated to redness, the water is expelled, and the 
anhydrous columbic acid remains.! 



AJYTIMOJYY. Symb. Sb. Equiv. 64.6. Sp. gr. 6.702 

History. Antimony was discovered by Basil Valentine, 
n the fifteenth century. It derived its name from anti monk, 



* Tantalum, discovered by Ekeberg, is identical with this metal. 

t The equiv. for antimony is considered by many late writers on chem- 
istry to be double the number in the text, 129.2. The same is true of a 
few other substances, which are noticed in their proper places. 
12* 



274 Metals. — A ntimony. 

from its having proved fatal to some monks, to whom it was 
given as a medicine. 

It is found native in Sweden, France, and the Hartz ; but 
generally occurs as a sulphur et. 

Process. It may be obtained by heating the native sul- 
phuret in a covered crucible, with half its weight of iron- 
filings ; the sulphur unites with the iron, and the metal ap- 
pears in the bottom of the crucible. Procured in this way, 
it is not absolutely pure, and, for chemical purposes, it should 
be procured by heating the oxide with an equal weight of 
cream of tartar. 

Properties. A brittle metal, of a white color ; fuses at 
810°, and, on cooling, has a lamellated texture, and often 
yields crystals ; burns with great brilliancy when placed on 
ignited charcoal, under a current of oxygen gas. 

Compounds of Antimony. 

JSesquioxide of Antimony (2Sb -j- 30. 153.2) is obtained 
by subjecting antimony in a covered crucible to a white heat, 
and then exposing it to the air ; a white vapor arises, and 
condenses ir fine crystals of silver whiteness. 

It is the only oxide which forms regular salts. It is the 

base of emetic tartar, • the tartrate of antimony and po- 

tassa. The test of antimony in solution is the hydrosulphuric 
acid, which yields an orange-colored precipitate. 

Antimonious Acid (2Sb-|-40. 161.2) is generated when 
the oxide is exposed to heat in open vessels. It is white 
when cold, and yellowish when heated ; very infusible and 
fixed in the fire, by which it is distinguished from the oxide ; 
insoluble in water and in acids, after being heated to redness. 

Antimonic Acid (2Sb -|-50. 169.2) may be obtained as a 
white hydrate, either by digesting the metal in strong nitric 
acid, or by dissolving it in nitrohydrochloric acid, concen- 
trating by heat to expel excess of acid, and throwing the 
solution into water. 

It is decomposed at a red heat, and converted into anti* 
monious acid. 

Sesqw 'chloride of Antimony (2Sb-{-3Cl. 235.46) is generated by the 
spontaneous combustion of antimony in chlorine gas. It is a soft solid, 



Uranium. 275 

palled builer of antimony ; easily fused, and deliquesces when ex- 
posed to the air.* 

Sesquis at phuret of Antimony. 28b -J- 3S. 177.5. This is the princi- 
pal ore of the metal, and iience is generally employed in making the 
preparations of antimony. It is of an earthy appearance, but is some- 
times found in acicular crystals, of a red-gray color and metallic lustre ; 
sp. gr. I.b'2. It may be formed artificially by fusing together antimony 
and sulphur. 

Oxysul phuret of Antimony is composed of 2 equiv. of 2 Sb-f-3S 
and 1 equiv r . of 2Sb0 3 =508.2. This occurs native — the red antimony 
of mineralogists. Glass, Liver, and crocus of antimony are of a similar 
nature. 

Krrincs Mineral is formed by boiling the sesquisulphuret with a 
solution of potassa or soda. On neutralizing the cold solution, a simi- 
lar substance, the gold c?t sulphur et, is precipitated.! 

Alloys. Printers 1 types are formed of 3 parts of lead, 1 
of antimony, and a little copper. 

Pewter is an alloy of 12 parts of tin, 1 of antimony, with 
a small addition of copper. The white metal for teapots is 
an alloy of 100 parts of tin, 8 of antimony, 2 of bismuth, and 
2 of copper. 



URAMUM. Symb. U. Equiv. 217. Sp. gr. 9. 

Uranium was discovered by Klaproth, in 1789. It derives 
its name from the planet discovered the same year, (Uranus.) 
It exists in pitch blende, and is obtained from it by heating 
the ore to redness, and digesting its powder in pure nitric 
acid, diluted with 3 or 4 parts of water. Its properties are 
not well known. 

Protoxide of Uranium (U -f- O. 225) is obtained by de- 
composing the nitrate of the sesquioxide by heat. It is of a 
dark green color, very infusible, and readily oxidized by 
nitric acid ; used in the arts to give a black color to porce« 
lain. 



* Bichloride of antimony; 2Sb-j-4Cl. 270.88. Perchloride of anti- 
mony ; 2Sb -\-oC\. 306.3. Oxychloride of antimony ; 2 equiv. of 2Sb -f- 
3C1. and 9 equiv. of Sb0 3 = 1849.72. Bromide of antimony, composi- 
tion unknown. 

t Bisulphuret of antimony ; 2Sb-|-4S. 193. G. Persulphuret of anti- 
mony ; 2Sb-f 5S. 209.7. 



276 Metals. — Cerium — Bismuth. 

Sesquioxide of Uranium (2U -\- BO. 458) is of a yellow 
color, and combines with acids and alkaline bases. 

The ProtocJdoride of Uranium, (U -f- CI. 252.42 ;) the Sesquichloridi 
of Uranium, (2U -}-3Cl. 540.26,) and the Sulphur et of Uranium, are un 
important compounds. — (See Turner, page 380.) 



CERIUM* Symb. Ce. Equiv. 46. 

Cerium was obtained, by Hisinger and Berzelius, from a 
mineral called cerite. It exists also in the mineral called 
allaniie, as an oxide, which is very difficult to be reduced to 
the metallic state. Yauquelin obtained a small globule, not 
larger than a pin's head, which was not acted upon by any 
of the simple acids, and but slowly dissolved by the nitro- 
hydrochloric. 

Compounds of Cerium. 

Protoxide of Cerium (Ce-j-O. Eq. 54) is a white powder, 
insoluble in water. The salts, which are soluble, have an 
acid re-action. 

Sesquioxide of Cerium (2Ce -f-30. 116) is obtained from cerite, and is 
a fawn-red substance, soluble in several of the acids. 

Protoehloride of Cerium. Ce+Cl or CeCl. 46 -f- 35.42 = 81.42. 

Sesquichloride of Cerium. 2Ce + 3C1 or Ce 2 CP. 92 -f 1 06.26 = 1 98.26. 

Protosulphuret of Cerium. Ce-f-S or CeS. 62.1. — (See Turner's 
Chemistry, p. 381.) 

BISMUTH. Symb. Bi. Equiv. 71. Sp. gr. 9.822. 

Native Bismuth occurs in crystals, octohedra, or cubes, 
containing arsenic and cobalt. It is also found combined 
with sulphur- and oxygen, from which it is obtained by the 
aid of heat and charcoal. 

Properties. It is a brittle solid, generally composed of 

broad plates of a reddish-white color, very fusible; melts at 

476° Fahr., and forms very fine crystals by slow cooling. 

Exp. For this purpose, fuse a quantity of it in a crucible, and let it 
Cool until a crust is formed; break the crust and pour out the fluid be- 

* So called from the planet Ceres, discovered about the same period 



Titanium. 277 

Heath ; the inner surface will be lined with beautiful crystals. Under 
the compound blowpipe it burns with much brilliancy, producing yellow 
fumes of protoxide. 

Protoxide of Bismuth (Bi-f-O. 79. Sp. gr. 8.211) may 
be formed as above. It forms salts, most of which are white ; 
sublimes at a high temperature ; fuses at a full red heat into 
a brown liquid. If the nitrate of the protoxide be thrown 
into water, a white precipitate is thrown down, formerly 
called magistery of bismuth, and pearl white, which is some- 
times used as a paint, for improving the complexion. 

Sesquioxile of Bismuth (2Bi-j-3G\ 166) is formed by fusing potassa 
with the protoxide of bismuth. It is a brown, heavy powder, little dis- 
used to unite with acids, or alkalies. 

Chloride of Bismuth (Bi -f- CI. 306.42) is formed by the spontaneous 
combustion of bismuth in chlorine gas, formerly called butter of bismuth 
tt is of a grayish-white color, and granular texture. 

Bromide of Bismuth. Bi -f Br. 71 -f 78.4 = 149.4. 

Sulphuret of Bismuth (Bi-f-S. 87.1) is found native. 



TITANIUM. Symb. Ti. Equiv. 24.3. Sp. gr. 5.3. 

Titanium was first noticed by Mr. Gregor, of Cornwall. 
Klaproth gave it the name of titanium, after the Titans of 
ancient fable. But its properties were determined by Wot 
laston, in 1822, who found it in the slag of an iron-smelting 
furnace in South Wales. 

Properties. Its color is red, resembling copper. It exists 
in small cubes, which are so hard as to scratch rock-crystal, 
and very infusible. It generally contains traces of iron. 
The pure metal is obtained by heating the chloride with am- 
monia in a glass tube, when it appears in the form of a deep 
blue colored powder, which is apt to take fire, if exposed to 
the air when warm. 

Compounds of Titanium. 

Oxide of Titanium (Ti -f- O. 32.3) is obtained by exposing titanic acid 
to a strong heat in a black-lead crucible. It is of a purple color. 

Titanic Acid, (Ti-j-20. 40.3,) also called peroxide of titanium, exists 
\n the minerals annta.se and rutile, from which the acid is obtained by 
vhe aid of heat and hydrosulphuric acid gas* 

* — . — - „____^__ 

* For processes, see Turner's Elements. 



2T8 Metals.— Tellurium. 

Properties. Titanic acid is of a white color ; very infusi- 
ble, and when once ignited, insoluble in acids, except in the 
hydrochloric. It is a feeble acid, resembling the silicic. If 
it is ignited with potassa, and dissolved in hydrochloric acid, 
a solution of gall-nuts will produce an orange-red color, which 
is very characteristic of titanic acid. 

Bichloride of 'Titanium (Ti + 2C1. 95.14) was discovered in 1824, by 
Mr. George, of Leeds, by transmitting dry chlorine gas over titanium 
at a low red heat. 

Properties. A transparent, colorless. liquid, which boils 
at 212°. The density of its vapor is 6.015; combines with 
water with explosive violence from the evolution of intense 
heat; on exposure to the atmosphere, it emits dense white 
fumes, of a pungent odor, similar to chlorine. 

Bisulphuret of Titanium. Ti + 2S. Eq. 24.3 + 32.2 — 
56.5. 

TELLURIUM. Symb. Te. Equiv. 64.2. Sp. gr. 6.115. 

Tellurium is a rare metal, found only in small quantities in 
Transylvania and Connecticut. It was first noticed by Mul- 
ler, in 1782, but its existence was more fully established in 
1798, by Klaproth, who called it tellurium, from tellus, the 
earth. It is found chiefly in combination with gold and 
silver. 

Properties. It is a brittle metal, of a bright gray color ; 
very infusible and volatile. Heated in the air, it burns with 
a sky-blue flame, edged with green; placed upon charcoal 
before the blowpipe, it inflames with violence, and flies en- 
tirely off in gray smoke, having a peculiarly nauseous smelh 

Compounds of Tellurium. 

Tellurous Acid, (Te + 20. 80.2,) also called oxide of tel- 
lurium, is generated by the action of nitric acid on tellurium. 
It is a white, granular powder, resembling in many of its 
properties the titanic, and several other feeble acids. Its 
aqueous solution reddens litmus paper. 

The other compounds are the Telluric .tfa'd, (Te -f- 30. 88.2;) Chlo- 
ride of Tellurium, (Te + CI. 99.62;) Bichloride, (Te-f-2Cl. 135.04;) 
Bisulphuret, (Te-}-2S. 96.4;) Persulphuret and Hydrotelluric Acid^ 
(Te-j-H, 65.2.) 



Copper. 279 

COPPER. Symb.Cu. Equiv. 31.6. Sp. gr. 8.895. 

Copper, from cuprum, a name derived from the island 
Cyprus, has been known from the remotest ages. 

Natural History. It is found native, and in combination 
with other substances, especially with sulphur. The copper 
of commerce is chiefly obtained from the native sulphurets. 
It exists in great abundance in Cornwall, and other parts of 
Europe, in Liberia, and in America. 

Schoolcraft found a mass of native copper about thirty 
miles from Lake Superior, which weighs, by estimation, 
2000 lbs. 

Process. It may be obtained perfectly pure, by dissolving 
the copper of commerce in hydrochloric acid, diluting the 
solution, and immersing in it a clean plate of iron, upon 
which the copper will be precipitated. 

Properties. Copper is distinguished from all other metals, 
except titanium, by its red color. It is very ductile and 
malleable; melts at 1996° Fahr. ; burns before the com- 
pound blowpipe with a beautiful green flame, and if a fused 
globule be thrown into a glass jar, two feet high, filled with 
water, it will pass in full ignition to the bottom, and remain 
some time at a red heat. 

Uses. Copper is one of the most useful metals, being em- 
ployed extensively in most of the arts of life. 

Compounds of Copper. 

Red, or Dioxide of Copper (2Cu + 0. 71.2) is found 
native in octohedral crystals. ~ 

Process. It may be prepared artificially, by heating, in a 
covered crucible, a mixture of 31.6 parts of copper-filings 
with 39 6 of the black oxide. 

Properties. It resembles copper in color ; sp. gr. 6.093 ; 
soluble in ammonia, and the solution is colorless*, but it 
absorbs oxygen on exposure to the air, which produces a 
blue color, owing to the formation of the black oxide. 



280 Metals. —Alloys of Copper. 

Black, or Protoxide of Copper. Cu -j- O. 39.6. This is the eoppet 
black of mineralogists, and is formed by the spontaneous oxidation ol 
other ores of copper. 

Properties. It varies from a dark brown to a bluish-black 
color, according to the mode of formation; combines with 
most of the acids, and its salts have a green or blue tint. J\ 
forms with ammonia a deep blue solution, which distinguishes' 
it from all other substances. The salts of the protoxide of 
copper are mostly distinguished by their color. Metallic 
copper is separated from the salts by a rod of iron or zinc 

Binoxide of Copper. Cu -f- 20. 31 6 + 16 = 47.6. 

Dichloride of Copper (2Cu -|- CI. 98.62) is formed by the spontane- 
ous combustion of copper-filings in chlorine gas. It is of various colors, 
white, yellow, and dark brown, according to the mode of preparation ; 
soluble in hydrochloric acid, but not in water. 

Chloriole of Copper ; Cu-{- CI. 67.02. Diniodide. of Copper; 2Cu -f- 
I. 63.2-fl26.3 = 189.5. Sulphuret of Copper (Cu + S. 47.7) is a 
constituent of copper pyrites^ in which it is combined with protosul- 
phuret of iron. Triphosphurct of Copper; 3Cu-J-P- 110.5. Subse- 
quiphosphuret ; 3Cu-J-2F. 126.2. Cyanide of Copper; Cu-f-Cy 
57.99. Disulphocyanide of Copper; Cu + CyS 2 . 63.2 -f- '(26.39 + 
32. 2) = 121.79. — (See Turner's Elements, p. 389.) 

Tests. The best mode of detecting copper in mixed liquids is the 
hydrosulphuric acid. The sulphuret, after being collected, and heated 
to redness in order to char organic matter, should be placed on a piece 
of porcelain, and be digested in a few drops of nitric acid ; sulphate of 
the protoxide of copper is formed, which, when evaporated to dryness, 
strikes the characteristic blue tint on the addition of ammonia. — T 

Alloys. The alloys of copper are very important and use- 
ful substances. 

Brass is an alloy of copper and zinc. The best brass 
consists of four parts of copper to one of zinc. Tutenag 
contains in addition a little iron. Tombac, Dutch Gold, Si" 
milor, Prince Rupert's Metal, and Pinchbeck, contain more 
copper than brass. Bell-metal and Bronze are alloys of cop- 
per and tin. The best proportion for bell-metal is 3 parts 
of dapper to 1 of tin ; for bronze, 8 to 12 of tin to 100 of 
copper. In these alloys, according to Dalton, the elements 
combine in definite proportions. 

Poisonous Properties of Copper. Copper vessels used for 
culinary purposes should be coated with tin,, as the oxide is 
poisonous. This is done. by making the surface of the copper 
bright, rubbing over a little sal-ammoniac to prevent oxidation, 
and then heating the vessel and rubbing it with rosin and tin. 



■■ 



Lead. 281 

LEAD. Symb. Pb. Equiv. 103.6. Sp. gr. 11.352. 

Lead was well Known to the ancients. It is rarely found 
native, but its ores are abundant, the most important of which 
is the sulphuret or galena, from which the pure metal is 
chiefly obtained.* Berzelius obtained the metal perfectly 
pure by heating the pure nitrate of lead, mixed with charcoal, 
in a Hessian crucible. 

Properties. The properties of lead are generally well 
known. It is of a bluish-white color, soft, malleable, and 
ductile; fuses at 612°, and by slow cooling, crystallizes in 
octohedra. The proper solvent of lead is nitric acid. 

Compounds of Lead. 

Protoxide of Lead (Pb + O. 11L6. Sp. gr. 9.4214) is 
prepared by heating the metal to a high temperature, and col- 
lecting the gray film which forms on the surface. This is 
exposed to heat in open vessels, until it acquires a uniform 
yellow color, and constitutes the massicot, and when partially 
fused, the litharge of commerce. This is always mixed with 
the red oxide ; it is obtained perfectly pure by adding ammo- 
nia in excess to the nitrate in solution, washing the precipi- 
tate in cold water, and, when dry, heating it to redness for an 
hour in a platinum crucible. 

Propei'tics. Its color is red when hot, but acquires a rich 
lemon-yellow when cold ; fuses at a bright red heat, and, after 
fusion, has a highly-foliated texture ; insoluble in water ; unites 
with acids, and forms the base for all the salts of lead. 

It is precipitated from its solutions by pure alkalies as a 



* Process. The ore, in the state of coarse powder, is heated in a 
reverberatory furnace, when part of it is oxidized, yielding sulphate of 
protoxide of lead, sulphuric acid which is evolved, and free oxide of 
lead. These oxidized portions then re-act on sulphuret of lead, by the 
ro-action of 2 equivalents of oxide of lead, and 1 of the sulphuret ; 
3 equivalents of oxide of lead and'l of sulphuric acid result, 
while 1 equivalent of the sulphuret and 1 of the sulphate mutually 
decompose each other, giving rise to 2 equivalents of sulphurous acid, 
and 2 of metallic lead. The lead of commerce commonly contains 
»ilver. iron, and copper. — T. 



232 Metals. — Lead 

white hydrate, which is re-dissolved by potassa in excess , as 
a white carbonate, which is the well-known pigment white 
lead, by alkaline carbonates ; as a white sulphate, by soluble 
sulphates ; as a dark brown sulphuret by hydrosulphuric acid t 
and as a yellow iodide of lead, by hydriodic acid, or iodide 
of potassium. — T. 

Metallic Lead is separated from the salts of the protoxide 
by iron or zinc. 

Exp. In a solution of 1 part of acetate of lead in 24 parts of water, 
contained in a glass bottle, suspend a piece of zinc by a thread. The 
lead will be deposited upon the zinc in a form resembling a tree — a 
peculiar appearance, called arbor Saturni. 

Uses. Protoxide of lead enters into the composition of 
flint-glass, and is employed for glazing earthen-ware and por- 
celain. 

Peroxide of Lead (Pb-$- 20. 119.6) is formed by the action of nitric 
acid upon the red oxide, or minium of commerce. It is of a puce color, 
insoluble in water, and resolved by strong oxygen acids into a salt of 
the protoxide and oxygen gas. 

Red Oxide of Lead (3 Pb + 40. 342.8) is prepared by 
heating lead in the air nearly to the point of fusion, by which 
it is oxidized. It is then exposed to a temperature of 600° 
or 700°, while a current of air passes across its surface. It 
slowly absorbs oxygen, and is converted into the minium of 
commerce. It is employed as a pigment, and in the manu- 
facture of flint-glass, but does not unite with acids and form 
salts. 

Chloride of Lead (Pb-f-Cl. 139.02) is obtained by adding hydro- 
chloric acid to a solution of acetate or nitrate of lead. It is sometimes 
called horn lead ; dissolved in hot water, it appears, on cooling, m 
small, acicular, anhydrous crystals, of a white color. 

Iodide of Lead; Pb-f-1. 229.9. Bromide of Lead; Pb-fBr. 182 
Fluoride of Lead ; Pb -f F. 122.28. Sulphuret of Lead ; Pb -4- S. 119.7. 
Fhosphuret of Lead and Carburet of Lead, composition uncertain. Cy- 
anide of Lead; Pb-J-Cy. 129.99. — (See Turner's Elements, p. 393.) 

The salts of lead are generally poisonous, of which the 
carbonate is the most virulent. 

Alloys of Lead. Common pewter is an alloy of 20 parts 
of lead and 80 of tin. Fine solder consists of 1 part of lead 
and 2 of tin, and is employed for tinning copper. Coarse 
solder contains one fourth of tin, and is used by plumbers, 
Pot metal is an alloy of lead and copper. 



Mercury. 283 

lECT. 3. METALS, THE OxiDES OF WHICH ARE REDUCED 
TO F*iE METALLIC STATE BY A RED HEAT. 

MERCURY, or QUICKSILVER. 

Sjmb. Hg. Equiv. 101,26 Sp: gr. 13.568. 

Mercury was well known to the ancients. Its principal 
ore is the sulphuret or native cinnabar, from which it is 
separated by distillation with quick lime, or iron-filings. 

Properties. Mercury is the only metal which retains its 
liquid form at common temperatures, It is of a tin-white 
color, and strong metallic lustre; boils at 662° Fahr., and 
congeals at 40° below zero, in which state it is malleable, 
and has an increased specific gravity 15.612. It is not tar- 
nished by exposure to cold, moist air, unless it contain other 
metals. It is sometimes adulterated with an alloy of lead and 
bismuth, which renders it less fluid and volatile, leaving a 
^ residuum when boiled in a silver spoon. 

Mercury is not acted upon by any of the acids except the 
sulphuric and nitric. 

It is used for collecting those gases which are absorbed by 
water ; also for barometers, thermometers, and for forming 
connections in voltaic circles. 

Compounds of Mercury. 

Dioxide of Mercury (Hg 2 0. 210.52) is prepared by 
mixing calomel with pure potassa in excess in a mortar, and 
ftirring it briskly to effect a rapid decomposition. The pro- 
toxide is then washed in cold water, and left to dry in a dark 
il ace. 

Properties. It is a black powder, insoluble in water, corn- 
Dining with acids, and bui feebly with alkalies. The alkalies 
precipitate it from the solution of its salts, as a black protox- 
. ide. The best test of its presence is the hydrosulphuric 
tcid, by which is thrown down a black disulphuret, 



284 Metals. — Mercury, 

Protoxide of Mercury (Hg O. 109.26) is commonly 
known by the name of red precipitate.* 

Process. Protoxide of mercury may be prepared by dissolving mer- 
cury in nitric acid, and exposing the nitrate thus formed to a tempera- 
ture just sufficient to expel the whole of the nitric acid. It may also b* 
formed by exposing mercury in a matrass, with a long tube, to the 
agency of heat and air, for the space of three or four weeks. 

Properties. It exists in shining, crystalline scales, nearly 
black when hot, and red when cold; slightly soluble in 
water. The solution has an acrid, metallic taste, and is poi- 
sonous. 

This oxide is separated from all acids by the carbonated 
fixed alkalies, and is reduced to the metallic state by copper. 

Dichloride of Mercury (Hg2-|- CI. 237.94) is common- 
ly called calomel, and was first mentioned in the seventeenth 
century, by Crollius. 

Process. It may be obtained by bringing chlorine gas in contact 
with mercury, but it is more commonly prepared by sublimation. This 
is done by mixing 1 equiv. of the chloride with 1 equiv. of mercury, 
until the metallic globules entirely disappear, and then subliming. 
To purify it from corrosive sublimate, which is always mixed with it, 
when first prepared, it must be reduced to powder, and well washed, 
when it will be fitted for chemical or medical purposes. The Di- 
chloride is also found native, and called horn quicksilver. 

Properties. When obtained by this process, calomel ex- 
ists in semi-transparent, crystalline cakes, of a yellow color 
when warm, but white when cold ; sublimes a little below 
a red heat, and a part of it is resolved into mercury, and 
the chloride. It is insoluble in water, and is decomposed 
by the pure alkalies. 

Used extensively for medical purposes; acts powerfully 
upon the glandular system. 

Chloride of Mercury (Hg-j- CI. 136.68) is formed by heating mer- 
cury in chlorine gas. During the process, the metal burns with a pale 
red flame. It is prepared for medical purposes by subliming a mixture 
of sulphate of the protoxide of mercury with chloride of sodium, or 
sea- salt. 

Properties. Chloride of mercury, commonly called cor- 
rosive sublimate, is a most virulent poison. It is white, semi- 
transparent, and crystalline in its texture; taste acrid and 
nauseous; more soluble in alcohol than in water ; sp. gr. 5.2 
It sublimes in the form of a dense, white vapor 5 when heated 

* This is the hydrargyri oxidum rubrum of the pharmacopolist. 



Compounds of Mercury. 285 

powerfully affecting the mouth and nose-; soluble in hydro- 
chloric, nitric, and sulphuric acids, and is decomposed by 
the alkalies, and several of the metals.* 

Tests. Place a drop of the suspected liquid on polished gold, and 
touch the moistened surface with the point of a penknife ; the part 
touched will instantly hecome white, owing to the formation of an 
amalgam of g:>ld. 

Some animal and vegetable substances convert the bichloride into 
calomel ; the best is albumen, made by mixing the white of an egg in 
water ; hence the white of an egg is an antidote to poisoning by cor 
rosive sublimate. 

Disulphuret of Mercury. Hg2-j-S. 226.62.* 

Sulphurct of Mercury (Hg-{-S. 117.36) maybe formed by fusing 
sulphur with six times its weight of mercury, and subliming in close 
vessels. 

Properties. When thus obtained, it has a red color, and 
is known by the name of factitious cinnabar. When reduced 
to powder, its tint is greatly improved, and constitutes the 
well known pigment, vermilion. The native cinnabar is a 
sulphuret, and is the principal ore of mercury. 

Ethiops Mineral is a mixture of sulphur and the Sul- 
phuret, and may be formed by triturating equal parts of sul- 
phur and mercury, until the globules of mercury disappear. 

Dicxjanide of Mercury (Hg2 -j- Cy. 236.91) is prepared by boiling a 
solution of Prussian blue with an equal weight of peroxide of mercury 
in powder, until the blue color of the pigment entirely disappears. 
The solution, on evaporation, yields quadrangular prisms of dicyanide 
of mercury. It is colorless, inodorous, and highly poisonous. 

Amalgams. Mercury combines with most of the metals, 
and forms a class of compounds called amalgams. An 
amalgam of one part of potassium and seventy of mercury 
is hard and brittle ; on adding mercury to the liquid alloy 
of potassium and sodium, solidification and combustion 
ensue. Two parts of mercury, one of bismuth, and one of 
lead' form a liquid amalgam, from which cubic crystals of 
bismuth are slowly formed. The combination of mercury 
with those metals which are not easily oxidized, enables 
them to combine with oxygen ; hence gold and silver, in 
combination with mercury, are easily oxidized by heat and 
air. With tin, it forms an amalgam for coating mirrors. 

* By considering the equivalent of mercury at 101.26, the names of its 
compounds, in order to conform to the nomenclature, are changed in tho 
the text: dioxide for protoxide, protoxide for oinoxide, disulphuret for 
pTtosulphuret, &c. 



286 Metals. — Silver. 



SILVER* Symb. Ag. Equiv. 103. Sp. &. 10.51. 

Silver has been known from the earliest ages. It is found 
native, and in combination with other substances. The 
native silver occurs in octohedral or cubic crystals, seldom 
perfectly pure ; it. is generally found in primitive formations; 
Peru and Mexico contain the richest mines of native silve? 
which are known. 

Preparation. Pure silver may be obtained from standard 
silver, by dissolving it in nitric acid and introducing a clean 
piece of copper. The metal will be precipitated upon the 
copper; this is then to be washed in pure water, and di- 
gested in ammonia to remove the copper. A better pro- 
cess is to decompose the chloride of silver by carbonate of 
potassa. 

Silver is often obtained from the argentiferous sulphuret 
of lead, by a process called cupellation.i Some of the ores 
are also reduced by amalgamation with mercury, and the 
mercury expelled by heat. 

Properties. Silver has the clearest white color of all the 
metals. Its lustre, when polished, is surpassed only by pol- 
ished steel ; so malleable that it may be extended into leaves 
less than a ten thousandth of an inch in thickness, and so 
ductile that it may be drawn into wire finer than the human 
hair. It fuses at 1873° Fahr., and appears extremely brilliant. 

* Lat. argentum. 

t This process is conducted in the following manner : — The lead is 
Kept at a red heat, in a flat furnace, with a draught of air playing on 
its surface. The lead is thxis rapidly oxidized, while the silver is un- 
affected. As fast as the oxide is formed, it melts and runs off through 
an aperture in the sides of the furnace; so that, in the end, the lead is 
all removed. The button of silver which remains is then melted in a 
small furnace resting on a porous earthen dish made with bone ashes 
called a cupel, the porosity of which is so great that it absorbs any par 
tions of litharge which may remain on the silver. The cuj.el is prepared 
by driving pounded bone ashes into a small brass mould by means of 
a pestle. It should then be removed and dried on paper. The cupel 
is then placed in a muffle, which is made of clay, arched above, and 
closed on all sides except the front. The whole is then placed in a 
cupelling furnace, which has an opening in one of its sides to receive 
the muffle. This is a very important process, and much used by re- 
finers and assayers, in the analysis of alloyed silver. 



Compounds of Silver 287 

It is not oxidized by air or moisture, but is tarnished by 
sulphurous vapors, which act slowly upon it; it burns with 
a fine green light, and throws off fumes of oxide when ex- 
posed to the action of voltaic currents. None of the pure 
acids act upon it but the sulphuric and nitric; the latter is 
its proper solvent, with which it forms the nitrate which, 
after fusion, is the lunar caustic. 

Use Silver is one of the precious metals, and is used as 
a coin, and for various purposes of art. 

Oxide of Silver (Ag-f-O or AgO. 116) is best formed by 
mixing a solution of pure baryta with the nitrate dissolved 
in water ; it is of a brown color, insoluble in water, and 
easily reduced by a red heat. 

Fulminating Silver is a compound of oxide of silver and ammonia. 

Process. Precipitate nitrate of silver by lime water; and, after wash- 
ing and drying the precipitate, put it into a vessel of pure ammonia 
fur twelve hours; a black powder will be thrown down, which, when 
carefully dried, explodes violently by the gentlest heat, or by slight 
friction. Great care should be taken in its preparation, and it should 
be preserved in small quantities in paper boxes. 

By heating the solution, a more dangerous compound is formed. 

A compound similar to the above, but less dangerous, is formed by 
dissolving silver in nitric acid, and adding to the solution successive 
portions of alcohol. This substance is used in the preparation of small 
balls called torpedoes. 

Chloride of Silver (Ag + Cl. 143.42) is -the horn silver 
of mineralogists. 

Process. It is formed by mixing hydrochloric acid with 
a solution of oxide of silver. When first precipitated, it is 
white, but becomes almost black by exposure to the solar 
rays; insoluble in water, but very soluble in ammonia, by 
which it is usually distinguished from other chlorides. It is 
often employed in analysis as the means of ascertaining the 
amount of chlorine present in various compounds. 

Iodide of Silver (Ag-f-I. 234.3) is a greenish-yellow substance. 

Sulpkuret of Silver. Ag-j-S. 124.1. This is the silver glance of 
mineralogists. Silver has a strong affinity for sulphur. On passing a 
current of hydrosulphuric acid gas through a solution of lunar caustic, 
i dark brown precipitate subsides, which is a sulphuret of silver. 

Cyanide of Silver (Ag-f- Cy. 134.39) is a white, curdy substance 

Alloys of Silver. Silver is alloyed with most of the metals. 
With steel it forms an alloy used in cutlery ; with copper, 



288 Metals. — Gold. 

it forms the silver plate and coin,* which is the most useful 
of its alloys ; with mercury, it forms an amalgam, sometimes 
employed for plating copper. Thermometer scales and 
clock dials are usually silvered by an alloy of chloride of 
silver, chalk, and pearlashes. 

GOLD* Symb.Au. Equiv. 199.2. Sp. gr. 19.257. 

Gold was known to the ancients, and has always been 
highly valued, as the most precious of the metals. 

Natural History. Gold occurs native, alloyed with a little 
silver or copper. It crystallizes in cubes and octohedra ; it 
is found in large quantities in alluvial soils, and in the beds 
of certain rivers, especially on the western coasts of Africa 
and Peru, in Brazil and Mexico, in Europe and the United 
States.^ 

Process. Gold is generally separated by amalgamation 
and cupellation ; but the best mode is to fuse the gold with 
silver, so that the latter shall constitute J of the mass ; nitric 
acid will dissolve the silver, and leave the gold. This process 
is called quart ation. 

To obtain gold perfectly pure, dissolve standard gold in 
nitrohydrochloric acid ; evaporate the solution to dryness, 
re-dissolve it in distilled water, filter, and add to the solu- 
tion sulphate of the protoxide of iron ; a black powder falls, 
which, when washed in dilute hydrochloric acid and distilled 
water, yields, on fusion, a button of pure gold. 

Properties. Gold is distinguished from all other metals 
by its yellow color ; it exceeds all others in ductility and 
malleability; it may be beaten into leaves not exceeding 
sWoinr °f an mcn m thickness ; it is very flexible and soft ; 
fuses at 2016° Daniell, and appears of a brilliant green color. 

* The standard silver of Great Britain contains ll^j- of pure silver, 
and A§. of copper ; that of the United States, 1 part by weight of 
copper, and 9 of silver. The dollar weighs 412^- grs., and the dime 
41£ grs. 

t Lat. aurum. 

% The gold from all the mines in the United States, in 1836, amounted 
to 467,000 dollars, 148,100 dollars of which were from North Carolina 



Compounds oj Gold. 289 

It is not easily oxidized, even in the state of fusion ; but, on 
subjecting a fine wire to an electric discharge, a purple 
powder is produced, which is probably an oxide ; it is readily 
dissolved by nitrohydrochloric acid. 

Protoxide of Gold (Au-j-O. 207.3) is formed by adding 
a cold solution of potassa to the protochloride ; a precipitate 
falls, of a green color, which changes spontaneously into me- 
tallic gold and teroxide. 

Binozide of Gold (Au-f-20. 215.2) is formed by the combustion of 
gold. 

Teroxide of Gold (Au + 30. 223.2) is the only well- 
known oxide of gold. 

Process. Dissolve 1 part of gold in the usual way, render it quite 
neutral by evaporation, and re-dissolve in 12 parts of water; to 
the solution add 1 part of the carbonate of potassa, dissolved in 
twice its weight of water, and digest at about 170°; carbonic acid 
gradually escapes, and the hydrated teroxide, of a brownish-red 
color, subsides. After being well washed, it is dissolved in colorless 
nitric acid of sp. gr. 1.4, and the solution decomposed by admixture 
with water. 

The hydrated teroxide is thus obtained quite pure, and is rendered 
anhydrous by a temperature of 212° Fahr. — T. 

Properties. The hydrate is yellow, but the anhydrous 
teroxide is nearly black, insoluble in water, and completely 
decomposed by solar light, or a red heat. With alkalies it 
acts the part of a weak acid, and was called by Pelletier 
auric acid. When the teroxide is kept in ammonia for the 
space of a day, a detonating compound of a deep olive color 
is formed. It is composed of 1 equiv. of gold, 2 of nitro- 
gen, 6 of hydrogen, and 3 of oxygen. 

The Fulminating Gold is a similar compound. 

Process. Add pure liquid ammonia to the dilute chloride. 
The precipitate which is formed will be re-dissolved if too 
much alkali is used; filter the liquid, and wash the sediment 
several times in warm water ; dry it by exposure to the air, 
arid preserve it in small paper boxes. 

Erp. Hold, on the point of a knife, a small portion of the powder 
over the flame of a spirit lamp, and it will detonate violently. 

Exp. Place two or three grains on a sheet of copper, and explode it; 
it will force a hole through the copper ; a spark from the electrical 
machine, or from a flint, will not affect it ; but the slightest friction will 
cause it to explode ; hence the danger of forming it, or of putting it up 
in large quantities. 

13 



290 Metals. — Gold. 

Protochhride of Gold. Au + CI. 234.62. 

Ter chloride of Gold (Au + 3C1. 305.46) is obtained by 
concentrating a solution of gold, in ruby-red crystals. This 
is the compound from which pure gold is obtained, and also 
most of the preparations of gold. 

Exp. When a strong aqueous solution of the terchloride is shaken 
with an equal volume of ether, two fluids result, tl»e lighter of which 
is an ethereal solution of gold. 

Exp. When a piece of charcoal is immersed in the aqueous solution, 
and exposed to the solar rays, it is covered with metallic gold. 

Exp. Ribbons are gilded by moistening them in this solution, and 
exposing them to a current of hydrogen gas. 

Exp. Add the protochloride of tin to a dilute aqueous solution of 
gold, and a purple-colored precipitate, the purple of Cassius, is thrown 
down. On fusing this powder with sand and borax, it forms a purple 
enamel, which is used for giving a pink color to porcelain.* 

Alloys of Gold. Gold forms alloys with most of the 
metals. With tin it forms a whitish brittle alloy. On 
this account the old chemists called tin diabolus metal* 
lorum. 

With lead, it forms a very brittle alloy. Even the fumes 
of lead destroy the ductility of gold. With copper, it forms 
the alloy used for standard gold ; which is perfectly malleable 
and ductile, hr rder than pure gold, and resists wear better 
than any other alloy, except that of silver; sp. gr. 17.157. 
The standard gold of the United States is an alloy of 1 part 
of an alloy of copper and silver, and 9 parts of pure gold. 
The British "sovereign" is 22 carats fine, that is, 22 parts 
of pure gold, and 2 of copper and silver. 

Water-Gilding. Mercury and gold combine, and form an 
amalgam much employed in gilding. It is applied to the 
surface of silver, and the mercury driven off by heat. 

Porcelain is gilded with gold powder, obtained by de- 
composing the chloride of gold; applied with a pencil, 
and burnished after exposure to the heat of a porcelain fur- 
nace. 



* Iodides of gold are formed by the action of iodide of potassium on 
the terchloride of gold. Protiodide of gold ; Au -f- 1 325.5. Teriodidi 
9 f gold; Au -f 3.1. 578.1. Tersulphuret of gold ; Au -f- 3S. 247.5. 



Platinum. 291 



PLATINUM. Symb. PI. Equiv. 98.8. Sp. gr. 21.25. 

Platinum is a very rare metal. It occurs native in Brazil, 
Peru, and other countries of South America, in rounded or 
flattened grains, mingled with other metals. It is found in 
larger quantities in the Ural Mountains. 

Properties. Platinum is the most dense of the metals, of 
a white color, resembling silver. It is malleable, and so duc- 
tile that it may be drawn into wire not exceeding y^ 2 ^ of 
an inch in diameter. It is soft, and easily welded, conduct- 
ing caloric with less facility than many other metals. It is 
not attacked by any of the pure acids. Its solvent is chlo- 
rine, or nitrohydrochloric acid. It is fused before the com- 
pound blowpipe, and by voltaic electricity. 

Spongy Platinum* has the remarkable property of causing 
oxygen and hydrogen gases to combine. Platinum foil will 
produce similar effects. This is due to the attraction of the 
gases for the platinum, and the repulsive power of the gases 
themselves. They are thus so condensed upon the surface 
as to bring the particles of the gases within the sphere of 
each other's attraction. 

Exp. Let a jet of hydrogen and oxygen upon a piece of spongy 
platinum ; the gas will soon be inflamed. 

Protoxide of Platinum (PI + O. 106.8) is prepared by digesting pro- 
tochloride of platinum in a solution of pure potassa. 

Binoxide of Platinum (PI -j-20 or PIO 2 . 114.8) is prepared with diffi- 
culty. According to Berzelius, it should be prepared by exactly de 
composing sulphate of binoxide of platinum with nitrate of baryta, and 
adding pure soda to the filtered solution, so as to precipitate about 
half of the oxide, which falls as a bulky hydrate, of a yellowish-brown 
color. 

Sesquioxide of Platinum. 2P1-J-30. 221.6. This oxide, of a gray 
color, is prepaied by heating fulminating platinum with nitrous acid. 

Protochloride of Platinum (Pl-f-Cl. 134.22) is formed when the 
bichloride is heated to 450°; half of its chloride is expelled, and the 
protochloride, of a greenish-gray color, remains. 

Bichloride of Platinum. P1-J-2C1. 169.64. This chloride is obtained 
by evaporating the solution of platinum in nitrohydrochloric acid to 
dryness, at a very gentle heat, when it remains as a red hydrate, 
which becomes brown when its water is expelled. — (See Turner, 
page 408.) 

* The sponge is prepared by adding ammonia to a solution of the 
chloride, and heating the precipitate to drive off the ammonia and 
chlorine. 



292 Metals. — Platinum. 

Protiodide of Platinum. Pl + I. 225.1. 

Biniodide of Platinum (PI + 21. 351.4) is prepared by the action of 
iodide of potassium on a rather dilute solution of bichloride of platinum. 
It is a black powder, tasteless, inodorous, and insoluble in water. 

Protosulphuret of Platinum (PI -f- S. 114.9) is prepared by heating 
the ammoniacal chloride with half its weight of sulphur, until all the 
sal-ammoniac and excess of sulphur are expelled. 

Bisulpkuret of Platinum (P1-J-2S. 131) is prepared by dropping a 
solution of bichloride of platinum into a solution of sulphuret of po* 
tassium. 

Fulminating Platinum may be prepared by the action of 
ammonia in excess on the sulphate of protoxide of platinum. 
It explodes at 420° with a very loud report, but does not 
explode by percussion. 

Palladium, Rhodium, Osmium, and Iridium, are found 
associated with platinum, but exist in small quantities. 

Palladium (Pd. 53.3. Sp. gr. 11.5) was discovered by 
Wollaston, and resembles platinum in color and lustre. 

Rhodium (R. 52.2. Sp. gr. 11) was also discovered by 
Wollaston. It is, when fused, of a white color, hard, and 
extremely brittle. It attracts oxygen at a red heat, and a 
mixture of peroxide and protoxide of rhodium is formed, 
not acted upon by any of the acids, unless alloyed with other 
metals. 

Osmium (Os. 99.7. Sp. gr. 7 to 10) was discovered by 
Tennant, in 1803. It is a black powder, which acquires 
metallic lustre by friction. When heated in the open air, it 
takes fire, and is readily oxidized and dissolved by fuming 
nitric acid. 

Osmic Acid (Os-(-40. 137.7) is formed by the oxidation 
of osmium by acids, by combustion, or by fusion with nitre 
or alkalies. Its vapor is very acrid, exciting cough, irritating 
the eyes, and producing a copious flow of saliva.* 

Iridium (Ir. 98.8. Sp. gr. 15.3629) was discovered by 
Tennant, in 1803, and about the same time by Descotils, of 
France. It is the most infusible of all metals, very brittle, 
and when polished resembles platinum. 

* Several metals have lately been added, Erbium and Terbium, found 
in connection with Yttria by Mosander, Pelopium and Niobium, discov- 
ered by Rose in Columbite, and Norium in Zircon by Svanberg : but as 
yet they are very rare and but little known. 



Satis. 293 

Latanium (La) is a metal recently discovered by Mosander. 
It is prepared by calcining the nitrate of cerium, mixed with 
nitrate of latanium. 



CHAPTER III. 
Ciass III. Salts, or Ternary Compounds. 

Salts comprise a very extensive class of compounds, in 
which acids combine with oxides, or with other compounds 
having similar properties. The oxide which combines with 
the acid, is termed a base, or salifiable base. 

The substances hitherto described are either simple bodies, 
or, with a few exceptions, compounds of two simple elements, 
and are hence called binary compounds. 

Salts, on the other hand, are composed of three or more 
simple bodies, and are hence termed ternary compounds, 
As^alts, under favorable circumstances, readily assume regu- 
lar crystalline forms, it seems proper, before proceeding to 
describe them, to present the subject of crystallization in 
general. 

Section 1. Crystallization. 

Most bodies, under favorable circumstances, may be made 
to assume the form of a regular geometrical solid. The 
process by which such a body is produced is called crystal- 
lization ; the solid is termed a crystal; and the science, the 
object of which is to study the form of crystals, is cry sial- 
ography. The condition, by which this process is peculiarly 
favored, is the slow and gradual change of a fluid into a 
solid, the arrangement of the particles being at the same time 
undisturbed by motion. This is exemplified during the slow 
cooling of a fused mass of sulphur or bismuth, or the spon- 



294 



Salts. — Cry sialography. 



taneous evaporation of a saline solution. The numerous crys« 
tals found in the mineral kingdom are due to the same cause 

The surfaces which limit the figure of crystals are called 
planes or faces. The lines formed by the junction of two 
planes are called edges, and the angle formed by two such 
edges is a plane angle ; a solid angle is the point formed by 
the meeting of at least three planes. — T. 

The forms of crystals are exceedingly diversified; they 
may be divided into primary and secondary forms. 

The primary forms are fifteen in number, and may be 
distributed as follows : — 1. Prisms; 2. Octohedrons; 3. Do- 
decahedrons. 

I. The prisms have either a six-sided base, or a four-sided 
base. 

(1.) Right Prisms. 

The bases are either right * or oblique, 
and the prisms are named according to 
their bases. 

1. The Hexahedron, or Cube, (Fig. 
95,) is a figure bounded by six square 
faces, and all the angles of its edges are 
equal to 90 degrees. 

2. The Right Square Prism (Fig. 96) 
differs from the cube in having its four lat- 
eral planes c, c, c, c, rectangles, and the ter- 
minal planes a a squares. 

3. The Right Rectangular Prism (Fig 
96) differs from the former in having the 
terminal planes a, a, rectangular instead of 
square. 





Fig. 95. 




\ ! 


\ 








\ 


s] 




Fig. 96. 


A « A 




c\ c c 


°j 




y ~& 


/ 



4. The Right Rhombic 
Prism (Fig. 97) differs 
from the two preceding 
only in its terminal planes 
a, b, being rhombs. 

5. The Right Rlwm- 
boiclal Prism (Fig. 98) 



Fig. 91 



Fig. 98. 




* The term right denotes that the lateral and terminal planes are 
inclined to each other at a right angle. It is used in opposition to 



Cry sialography. 



295 



differs from the preceding form in the terminal planes cc 
being rhomboids. 

6. The Regular Hexagonal Prism 
(Fig. 99) is bounded by six perpendicu- 
lar or lateral planes, and two horizontal 
or terminal planes, a, b, which are at right 
angles to them. 





Fig. 99, 


> 


<A <L_i> 


K^ 


] 


V. 


b 



Fig. 100. 



Fig. 101. 






(2.) Oblique Prisms. 

7. The Rhombohedron 
(Fig. 100) is bounded by 
six rhombic faces, of the 
same size and form. 

8. The Oblique Rhombic 
Prisms (Fig. 101) have the 
terminal planes a, a, rhombs, 
with the lateral planes forming oblique angles with them 

9. Oblique Rectangular Prism differs from the preceding 
in having the terminal planes rectangles. 

10. Oblique Rhomboidal Prism (Fig. 
102) differs from the two preceding forms 
in the terminal planes a, a, being rhom- 
boids. 

11. The Octohedrons are also named from 
their bases. The base of the octohedron 
is a section passing through four angles. 

11. Regular Octohe- 
dron (Fig. 103) has a Fig. 103. 
square base, a a a a, and y 
is contained under eight 
equilateral triangles — 
hence all its plane an- 
gles are equal to 60 de- g, 
grees. This figure is a 
regular solid of geom- 
etry. 

12. Square Octohe- 
dron (Fig. 104) has a 

square base, aaaa, and is bounded by eight faces, which are 
isosceles triangles. The base is always a square, the only 
• part of the figure which is constant. 

oblique, which signifies that the sides are not perpendicular, but form 
vi oblique angle with the terminal planes. — T. 




296 



Cry sialography. 



13. Rectangular Octohedron (Fig. 
105) has a rectangular base, a a a a, and 
is bounded by eight isosceles triangles, 
four of which are different from the other 
four. 

14. Rhombic Octohedron (Fig. 106) 
has a rhombic base, a a a a, and is con- 
tained under eight similar scalene trian- 
gles, but all its dimensions are variable. 




III. Dodecahedrons. 

15. There is but one pri- 
mary dodecahedron, called 
the rhomhic dodecahedron, 
(Fig. 107,) and is limited 
by twelve similar rhombic 
faces ; the faces incline to 
each other at an angle of 
120 degrees * 



Fig. 107. 




Secondary Forms. 

The secondary forms of crystals are very numerous, 
amounting to millions. The forms of a single mineral calta* 
reous spar have been found to be nearly a thousand ; but each 
of the secondary forms may be reduced to one or more of 
the primary, by a process called cleavage. This process is 
usually performed with a sharp instrument, by removing thin 
laminse from the faces, edges, or angles of the crystal. The 
surfaces exposed by splitting or cleaving a crystal, are 
termed the faces of cleavage, and the direction in which it 
may be cleaved is called the direction of cleavage. Some 
crystals are cleavable in one direction, and some in two, three, 
four, or more directions. 

Those which cleave in more than two directions may, by 
the removal of layers parallel to the planes in their cleavage, 



* The instrument used for measuring the angles, at which the planes 
of crystals meet or incline to each other, are called goniometers. — See 
Dana's Mineralogy, p. 32, New Haven. 1837. 



Theories of the constitution of Salts. 297 

be made to assume regular primary forms, whatever be their 
figure previous to cleavage. 

It was formerly supposed that each substance always had 
the same primary form ; but the discovery was made by 
Mitscherlich, in 1819, that identity of composition did not 
always indicate identity of crystalline form. 

To this new branch of science the term isomorphism 
(from long, equal, and juoQcpri, form) is applied.* 

The phenomena of crystallization are ascribed to cohesive 
attraction, or, more properly, to crystalogenic attraction. 

The crystallization of salts is most readily effected by dis- 
solving them in water, and evaporating the solution. 

Exp. Introduce into a large matrass a pound and a half of Glauber s 
salts, (sulphate of soda,) with a pound of water, and boil the mixture 
until all the salt is dissolved ; cork it tight, as the heat is removeu ^d 
let it cool. On taking out the stopper, the salt will suddenly crysid... 
lize, and the whole will become nearly solid. 

The water enters into the crystal in definite proportions, 
and is called the water of crystallization. The quantity of 
combined water is very variable in different crystals; such 
salts, when heated, dissolve, if soluble, in their own water 
of crystallization, undergoing what is termed watery fusion • 
some salts, when exposed to the air, lose their water of crys- 
tallization, and crumble down into a fine powder; this is 
termed efflorescence: others absorb water from the atmos- 
phere, and are said to deliquesce. 

Some salts enclose mechanically within their texture parti- 
cles of water, by the expansion of which, when heated, they 
burst with a crackling noise ; this is called decrepitation 

Theories of the constitution of Salts. 

I. The old and commonly received definition of a salt, is a 
substance formed by the union of two ^'elementary com- 
pounds. Thus one series of salts are formed by the union 
of oxides with oxides ; another by a combination of chlorides 
with chlorides, sulphurets with sulphurets, &c. That is, 
compounds belonging to the same series unite with each other 
.to form salts, and when compounds of different series aro 

■to* * See Turner, 5th ed, p. 429. 



298 . Chemistry. 

mixed together they do not unite, but generally decompose 
each other; thus when sulphuric acid is poured upon chlo« 
ride of sodium (common salt) the chloride is decomposed, and 
sulphate of soda and hydrochloric acid are formed. 

II. By some chemists the salts are divided into two classes. 
The first class includes those bodies constituted as above, and 
the second class such as are formed by the union of a simple 
body of the chlorine family with a metal, such as we have 
described as the chlorides, bromides, iodides, &c, of metals. 
And regarding hydrogen as a metal, the liydracids, hydro- 
chloric, hydriodic, hydrobromic are not acids, but salts ; and 
the fact that when the hydracids are brought in contact with 
a metal, the metal is substituted for their hydrogen, would 
',eem to be a good reason for placing them in the same class 
of compounds. If these views are correct, many of the oxy- 
gen acids are really salts, in which case the water is the 
oxygen base ; thus liquid sulphuric acid is a sulphate of 
water. (S0 3 -}-HG.) Nitric acid is a nitrate of water. 
(N0 6 .HO+3HO.) 

III. A third theory of the constitution of salts would reduce 
them all to Unary compounds. That is, one of the elements 
is what has been termed a compound radical, a compound like 
cyanogen acting in combination like a simple element. For 
example, when sulphuric acid is poured on zinc, sulphate of 
zinc is formed, and hydrogen evolved. The change in this 
case is explained by supposing that the hydrous sulphuric acid 
(SO 3 . HO) has the composition, S0 4 H, and that the zinc Zn 
takes the place of the hydrogen, and there results the salt, 
having the constitution S0 4 + Zn. The SO 4 is called the 
compound radical. This change, it will be seen, is precisely 
similar to that which takes place when hydrochloric acid 
(HC1) is poured on zinc, chloride of zinc (Cl-fZn) is formed., 
and hydrogen escapes. 

When oxygen acids act upon metallic oxides, as liquid nitric 
acid upon potassa, we may explain the change by consider 



Theories of the Constitution of Salts. 299 

ing the acid to be composed of NO-f-H, and the potassa of 
KO. NO 6 combines with K to form the nitrate of potassa, 
and the hydrogen of the acid and oxygen of the oxide unite 
and form water. In this way we may explain the formation 
of all the salts. The principal objection to the theory is 
found in the necessity of introducing a large number of these 
compound radicals which have never been isolated. They 
are, with a few exceptions, as cyanogen, purely hypothetical 
bodies ; but an argument is adduced for the existence of such 
radicals from the action of voltaic electricity in decomposing 
binary compounds, as the iodides, chlorides, &c, compared 
with its action upon what have been supposed to be ternary 
compounds, or oxygen salts. It requires the same quantity 
of electricity to decompose a binary compound ; but in the 
case of sulphate of soda, for example, if the water and the 
salt are both decomposed, which was supposed to be the case 
on the old theory, it ought to require twice the quantity of 
electricity, but it requires no more than to decompose water 
alone- If we consider the sulphate of soda to be composed 
of S0 4 -f-Na, this effect is easily explained. The current 
separates the SO 4 from the Na, and as the sodium (Na) ar- 
arrives at the negative electrode, it decomposes an equiv. of 
water forming NaO and H, which escapes ; the SO 4 also, on 
arriving at the opposite electrode, decomposes water with the 
formation of HSO 4 , while O escapes ; the decomposition of the 
water being a secondary action not due directly to the agency 
of the current. 

Another argument in support of the existence of such 
radicals is, that many of the acids, as nitric acid, have never 
been obtained free from the elements of water. Such a sub- 
stance as NO 6 has never been isolated, but N0 5 HO, and 
therefore NO^ + H may be its constitution. NO 6 would be a 
compound radical. Such a view cannot be objected to as an 

hypothesis ; but if it be made the basis of a system, there 

are certainly very strong reasons against it. 



800 Chemistry. 

Salts are divided into neutral, acid, and basic. 

1. A neutral salt consists generally of one equiv. of acid 
united to one equiv. of base, or the number of atoms of acid 
is equal to the number of atoms of oxygen in the base, 

2. The acid salts are of two kinds. 1st. Those in which 
water is present, in which case they are really double salts, 
water being one of the bases ; thus bisulphate of potash is a 
sulphate of potash and a sulphate of M?ater=S0 3 .KQ-j-SQ 3 HO. 
And 2dly. Those salts which do not contain water. These 
are the true acid salts, in which case the acid is in excess 
two or three equiv. of acid to one of base * thus the chromatea 
of potash (Cro 3 -f-KO, 2Cro 3 -{-KO and 3Cro 3 +KO) are good 
examples of acid salts. 

3. The basic salts have, on the contrary, two or more equiv. 
of base to one of acid. Thus, the neutral nitrate of copper 
has the formula N0 5 .CuO+3HO, but the basic nitrate NO 5 
HO-f-3CuO, in which case there are three equiv. of base, 
which take the place of three equiv. of water in the neutral 
nitrate. On this principle several basic salts may be formed 
by substituting the oxide of the metal for the oxide of hydro- 
gen. Sulphuric acid and oxide of zinc form such a series. 
Thus, 

S0 3 -f ZnO +7HO. SO 3 + 6ZnO +2HO. 

S0 3 +4ZnO+4HO. S0 3 +8ZnO. 

There are several neutral salts, however, which are bibasie 
and tribasic, as in the case of the three phosphates of silvei 
and some others. (See Kane's Chemistry.) 

4. Double salts. The double salts are composed of two 
simple salts. They generally consist of two acids and one 
base, or of two bases and one acid. In a few cases two bases 
and two acids are united. 

5. There are several families of salts formed by the union 
of sulphurets with sulphurets, chlorides, iodides, cyanides^ 
&c, with chlorides, iodides, cyanides, &c. These salts are 
similar in constitution to the oxygen salts. For example. 



Oxy- Salts. g 01 

one sulphuret performs the office of an acid, and another of a 
base; thus the sulphuret of arsenic is a sulphur acid, and 
sulphuret of potassium, the sulphur base. These two sub- 
stances combine and form arsenio-sulphuret of potassium ; 
such salts are termed sulphur salts. 

When chlorides, iodides, &c., combine with each other, 
they form a similar order, called the haloid salts; of which 
there are several families. 

The chlorides, iodides, &c, sometimes combine with me- 
tallic oxides and form a family of salts, called oxy-chlorides, 
&c. 

The hydro-salts are composed of hydracids, with ammonia 
and phosphuret of hydrogen. This order is discarded by 
many chemists. (See hydro-salts.) 

For a more detailed account of the several theories men- 
tioned above, on the nature, constitution, and classification 
of the salts, the student is referred to Kane's Chemistry - 
also to the works of Fownes, Graham, and others. 

If the theory of compound radicals be admitted in organic 
chemistry, as it generally is, there seems no good reasmi for 
rejecting it in the constitution of salts. But some chemists 
among whom is M. Gerhardt, explain the various reactions 
of organic compounds in such a way as to dispense with 
these hypothetical compound radicals; and until the doctrine 
is fully admitted in organic chemistry, it seems the safest 
course to adopt the common theory in regard to the constitu- 
tion of inorganic salts. In as much as the properties of salts 
are not altered by any theory respecting their nature, we 
have concluded to retain the old division of oxy-salts, hydro, 
salts, sulphur salts, and Haloid salts. 

Section 2. 
ORDER I.— OXY-SALTS. 
This order includes no compound the acid or base of 
which does not contain oxygen. AI] the powerful alkaline 



302 Salts. — Sulphates. 

bases, except ammonia, are protoxides of an electro-positive 
metal. If M represent an equivalent of any metal, M-f-C 
or MO is the strongest alkaline base, and generally the only 
one which the metal is capable of forming; a single equiv 
of acid neutralizes MO, forming a neutral salt. Thus, if 
an equiv, of sulphuric and nitric acids be represented by 
SO 3 and NO 5 , all the neutral sulphates and nitrates of the 
protoxide will be indicated by MO -j- SO 3 and MO + NO 5 ; 
hence it may be inferred, that, in each family of salts, there 
is a constant ratio in the oxygen of the base and that of 
the acid ; that for sulphates is as 1 to 3, and the nitrates 
as 1 to 5. If the base be a binoxide, the same relation 
is preserved. 

Salts sometimes combine with each other, forming double 
salts ; these are composed of two acids and one base, of two 
bases and one acid, or of two different acids and two differ- 
ent bases ; these were formerly called triple salts. 

Those salts which are formed by the same acid, combined 
with different bases, have many properties in common, and 
hence they are classed in the same family. 



1. Sulphates. 

Many of the sulphates occur native; of which, those of 
lime and baryta are the most abundant. They may all be 
formed by the action of sulphuric acid on the metals, their 
oxides, their carbonates, or by double decomposition. They 
vary in solubility in water, and are all decomposed at a white 
heat, and by carbonaceous matter with the aid of heat. 

Sulphuric Acid, which is the acid of all the sulphates, is 
readily detected by the chloride of barium — the acid having 
a stronger affinity for baryta than for any other alkaline 
base. 

The sulphates are a very numerous family of salts. The 
following are the most important : — 

Sulphate of Potassa, (KO + SO 3 . 87.25,) potassa sulphas s 



Sulphates. — Potassa — Soda. 303 

was formerly called sal de duohus. It may be prepared by 
neutralizing carbonate of potassa with sulphuric acid. 

Properties. Taste saline and bitter. Its crystals belong 
to the right prismatic system, and contain no water; soluble 
in 10 times their weight of water at 60°, and in 5 of boiling 
water. 

Bisulphate of Potassa. KO + 2S0 3 . 127.35; with 1 
equiv. of water, 136.35. This salt is prepared by heating 
the sulphate, with half its weight of sulphuric acid, in a 
platinum crucible. 

Properties. It has a sour taste, and reddens litmus 
paper;* is more soluble than the sulphates, and its crystals 
belong to the same order. It is used for cleaning coin, and 
other works in metal. 

Sulphate of Soda (NzO-\- SO*. 71.4; in crystals, with 10 
equiv. of water, 161.4) is well known as Glauber's salts. 
ft is found in the earth, and in the water of many springs. 
It is easily formed by saturating SO 3 with carbonate of 
•soda. 

Properties. Taste bitter, cooling, and saline. Its crys- 
tals belong to the right prismatic system ; effloresces on 
exposure to the air, and undergoes watery fusion when 
heated. 12. parts of the salt require 100 of water at 32° 
to dissolve them. Used in pharmacy, and in the manufac- 
ture of glass. 

Bisulphate of Soda. NaO-r-2S0 3 . 111.5; with 4 equiv- of water, 
147.5. 

Sulphate of Litha (LO-f-SO 3 54.45; in crystals, with 1 equiv. of 
cvater, 63.45) has a saline taste, very soluble and fusible, and crystal- 
lizes in flat prisms. 

Sulphate of Ammonia (H 3 N -f- SO 3 . 57.25 ; in crystals, with 2 equiv. 
of water, 75.25) sometimes occurs native in volcanoes, and near cer- 
tain small lakes in Tuscany. It may be prepared by neutralizing 
Bulphuric acid with carbonate of ammonia. It is contained in soot 
from coal. 

Properties. It crystallizes in long, flattened, six-sided 
prisms, soluble in 2 parts of water at 60°, and in an equal 
weight of boiling water ; effloresces in warm, dry air, losing 

* Unglazed paper, moistened in an infusion ot fitmus, and dried. 



804 Salts. — Sulphates. 

1 equiv. of water; yields its water of crystallization 05 
heat, fuses, and is decomposed, yielding nitrogen, water, 
and sulphate of ammonia. 

Uses. It is the source of the hydrochlorate of ammonia, which ia 
obtained by a mixture of common salt and sulphate of ammonia by 
sublimation. 

Sulphate of Baryta (BaO + SO 3 . 116.8. Sp. gr. 4.4) 
occurs native in great abundance, and is known by the 
name of heavy-spar. 

Properties. Insoluble in water, and is precipitated by 
adding sulphuric acid to any soluble salt of baryta. So 
delicate is baryta as a test of SO 3 , that 1 part of sulphate 
of soda in 400,000 of water is detected by it. It fuses at 
a high temperature into an opaque, white enamel. 

Uses. It is employed in the manufacture of jasper ware, and for #- 
paint under the name of permanent white* (See Baryta, page 227. f 

Sulphate of Strontia (SrO-)-S0 3 . 91.9) occurs native h 
beautiful crystals in Sicily, and also on Strontian Island 
Lake Erie. 

Properties. It has a blue tint, and is called celestine 
sometimes it is colorless and transparent ; nearly insoluble 
requiring 4000 parts of cold, and 3840 of hot water to 
dissolve it. Heated with charcoal, its acid is decomposed 
and sulphuret of strontium is formed. 

Sulphate of Lime (CaO-fSO 3 . 68.6; with 2 equiv. oi 
water, 86.6) occurs in nature in large quantities. Ever} 
variety of gypsum is the sulphate combined with 2 equiv. 
of water ; such as plaster of Paris, selenite, — which is a 
crystallized variety, — alabaster, a white, compact varie* 
ty, used in statuary, — and anhydrite, which contains no 
water. The salt may be formed by mixing, in solution, a 
salt of lime with any soluble sulphate. 

Properties. Crystals of anhydrite belong to the right, an< 
of gypsum to the oblique prismatic systems. It is nearly 
tasteless, soluble in 500 parts of cold, and 450 of boiling 



* It is the best paint for marking phials and jars in the laborator) 
It may be prepared by mixing the powder with oil and lampblack. 



Sulphates. 305 

water ; hence it is generally found in spring and rjver w ater, 
and especially in those waters called hard. Baryta will de- 
tect the sulphuric acid, and oxalic acid the lime. Heated to 
212° in vacuo, it parts with 1 equiv. of water, and. at 300° 
the whole ; in this state it is used as a cement. By mixing 
it with a certain portion of water, it hardens rapidly, and be- 
comes dry and solid ; on this account it is much used for 
taking impressions, for stereotype plates, and for casts, busts, 
and a great variety of purposes in the arts. It is used in 
agriculture as a mineral manure, and is highly useful to 
most soils. 

Sulphate of Magnesia (MgO + S0 3 HO. 69.8 ; in crystals, 
with 6 equiv. of water, = 123.8) was procured from the 
springs of Epsom, England, and hence called Epsom salt. 
It is found native, and constitutes the bitter salt and hair 
salt of mineralogists. Sometimes it is found incrusting the 
damp walls of cellars and new buildings. Many saline 
springs contain it. 

Process. But it is generally obtained from sea-water, and 
exists in the bittern which is left after the crystallization of 
common salt. It is obtained by decomposing the hydro- 
chlorate of magnesia contained in it with SO 3 . It may also 
be formed from the carbonate by adding sulphuric acid. 

Properties. It has a saline, bitter, and nauseous taste. 
Its crystals are small,, quadrangular prisms,* slightly efflores- 
cent in dry air, soluble in an equal weight of water at 60°, 
and f- of their weight of boiling water. They undergo watery 
fusion when heated, and are partially decomposed at a white 
heat. 

Sulphate of Mumina. 2A10 3 -j-S0 3 . 91.5; in crystals, with 9 equiv. 
of water, 172.5. 

Tersulphate of Mumina. 2A10 3 -f 3S0 3 . 171.7; in crystals, with 18 
equiv. of water, 333.7. 

The Hydrated Di sulphate is called Aluminite. 

Sulphate of Protoxide of Manganese. MnO + S0 3 HO. 84.8. 

Sulphate of Protoxide of Iron. FeO + S0 3 HO. 85.1; in 
crystals, with 5 equiv. of water, eq. 130.1. This is known 

* The larger crystals are generally right rhombic prisms 



306 Salts. — Sulphates. 

by the name of green vitriol, or copperas. It is prepared on 
a large scale for the arts, by exposing the native protosulphu- 
ret of iron to air and moisture ; the iron is converted into 
an oxide, and the sulphur into SO 3 ; they then combine and 
form the sulphate. It may also be formed by the action of 
SO 3 on the iron. 

Properties. Its taste is strongly styptic and inky. When 
pure, it does not redden the vegetable blue colors. Its crys- 
tals have a blue tint, and belong to the oblique prismatic 
system ; soluble in 2 parts of cold, and in f its weight of 
boiling water. It is used in the manufacture of fuming suK 
phuric acid and in dyeing. 

Ter sulphate of the Sequioxide. Fe 2 3 -f 3S0 3 . 200.3. 

Disulphate of the Sequioxide. 2Fe 2 3 -f SO 3 . 200.1. 

Sulphate of the Protoxide of Zinc, (ZnO + S0 3 HO. 89.4 ; 
with 6 equiv. of water == 143.4,) commonly called white vitriol, 
is formed by the action of dilute sulphuric acid on zinc. It 
is prepared in the arts by roasting the native sulphuret of 
zinc. 

Properties. It crystallizes, by spontaneous evaporation, in 
transparent, flattened, four-sided prisms, referable to a right 
rhombic prism, and isomorphous with Epsom salt. Taste 
strongly styptic, and, although a neutral salt, reddens vegeta- 
ble blue colors ; soluble in 2J parts of cold, and a less quan- 
tity of boiling water. 

Use. A powerful emetic, and poisonous if given in large 
doses. 

Sulphate of Protoxide of Nickel (NiO + S0 3 HO. 86.6^ 
crystallizes from its solution in pure water, in right rhombic 
prisms, and, like most of the salts of nickel, is of a green 
color. 

Sulphate of Protoxide of Cobalt (CO + S0 3 HO. 86.0) is 
formed by digesting dilute SO 3 with oxide of cobalt. On 
evaporation, it appears in the form of red crystals. 

Ter sulphate of the Sequioxide of Chromium. Cr 2 O s -\- 'J 
SO 3 . 200.3. 



Sulphates. 307 

Sulphates of the Oxide of Copper. 

The Disulphate (2CuO-t-S0 3 . 119.3) has not been ob- 
ia ned in a separate state. 

The Sulphate, or Blue Vitriol* (CuO + S0 3 HO. 88.7; in 
crystals, with 4 equiv. of water, 124.7) is formed by roasting 
the native sulphuret, or by dissolving the protoxide in dilute 
sulphuric acid, and crystallizing by evaporation. 

Properties. The crystals are of a blue color, and yield 4 
equiv. of water at 212°, and the whole at 430° Fahr., when 
it becomes a white powder. 

When ammonia is dropped into a solution of the sulphate, 
it forms a dark blue solution, from which, when concentrated, 
crystals are deposited by the addition of alcohol. This is the 
ammoniaret of copper of the U. S. Phar. 

Sulphate of the Oxides of Mercury. 

The Sulphate of Dioxide Hg 8 + SO 3 . 250.62) is formed 
when 2 parts of mercury are heated with 3 of strong sul- 
phuric acid, so as to produce effervescence. If a strong heat 
is employed, the 

Sulphate (HgO + SO 3 . 149.36) results, both being an- 
hydrous. When this sulphate (the salt employed for 
making corrosive sublimate) is thrown into hot water, a yel 
low salt, the 

Trisu/phate, ( 3lIgO + SO 3 . 671.66,) called turpeth min- 
eral, is generated. 

Sulphate of Oxide of Silver (AgO + SO 3 . 156.1) is depos- 
ed when sulphate of soda is mixed with nitrate of silver, 
md also by boiling silver with its weight of sulphuric acid. 

Properties. It is white, and easily fused ; soluble in 80 
times its weight of hot water, and deposits small, needle- 
shaped crystals on cooling. It forms with ammonia a double 
salt, consisting of 1 equiv. of oxide of silver, 1 of acid, 
and 2 of ammonia. It crystallizes in rectangular prisms, 
isomorphous with the double chromate and seleniate of oxide 
o c . silver and ammonia. 

* Great use is now made of this substance for exciting electricity in 
galvanic batteries. 



308 Salts.— Sulphates. 

Nitrosulphuric Acid, consisting of 1 part of nitric di» 
solved in 10 of sulphuric acid, dissolves silver, but scarcely 
acts upon copper, lead, or iron, unless diluted with water t 
hence its use in separating silver from old plated articles. 

Double Sulphates. 

Sulphate of Soda and Lme (NaOSO 3 -4- CaOSO 3 . 140) is the Glauber- 
ite of mineralogists, and occurs in the salt-mines of New Castle. 

Sulphate of Potassa and Magnesia (KOS0 3 4-MgOS0 3 ) is formed 
by mixing solutions of the two salts. 

Sulphate of Potassa and Alumina. KOS0 3 -f APO 3 . 3S01 
258.95, do. with 24 equiv. of water = 474.95. This salt, 
the common alum, is prepared by roasting and lixiviating cer- 
tain clays, containing iron pyrites, and adding to the Jyes a 
quantity of sulphate of potassa. It is obtained in Italy from 
alum-stone. Alum is also found in volcanic countries, pro- 
duced by the action of sulphurous vapors on rocks containing 
feldspar. 

Properties. It has a sweetish, astringent taste ; is soluble 
in 5 parts of water at 60°, and crystallizes in octohedrons. 
Ignited with charcoal, it forms Homberg's Pyrophorus. 

Exp. Take 3 parts of lampblack, 4 of calcined alum, and 8 of pearl- 
ashes ; mix them thoroughly, and heat them in an iron tube to a bright 
cherry-red, for one hour; on removal from the fire, the tube must be 
carefully stopped. This substance, when exposed to the air and 
breathed upon, ignites with slight explosions. The essential part is 
probably sulphuret of potassium, in minute divisions. 

Use. Alum is of great use in the arts, especially in dye- 
ing and calico-printing, because of its attraction for coloring 
matter. 

Ammonia Alum has the same form, appearance, and taste. 

Soda Alum is also similar, except that it contains 26 equi*. 
of water. 

Iron Alum is formed by mixing sulphate of potassa with 
tersulphate of sesquioxide of iron ; it resembles common 
alum in form, color, taste, and composition. 

Chrome Alums. The tersulphate of sesquioxide of chro- 
mium forms double salts, with the sulphate of potassa and 
ammonia, very similar to the preceding. 



Sulphites — Nitrates. 309 

Manganese Alum is formed by mixing a solution of ter- 
Bulphate of sesquioxide of manganese with sulphate of po- 
tassa. These salts all crystallize in the octohedral system, 
and are similar in composition, one oxide being substituted 
for another, to form the different varieties 

2. Sulphites. 

The salts of sulphurous acid have not hitherto been mi- 
nutely examined ; the sulphites of potassa, soda, and ammo- 
nia, are made by neutralizing those alkalies with sulphurous 
acid, and are soluble in water ; but most sulphites are spar- 
ingly soluble, if at all ; they are decomposed by the stronger 
acids. — (See Turner, 5th edit. p. 443.) 

3. Nitrates. 

The nitrates may be prepared by the action of nitric acid 
on metals, on the salifiable bases, or on carbonates. As 
nitric acid forms soluble salts with all alkaline bases, the 
acids of the nitrates cannot be precipitated by any re- 
agent. — T. 

The nitrates are all decomposed by a high temperature, 
and by the agency of heat and combustible matter ; hence 
they are much employed as oxidizing agents. The process 
of oxidation by nitre, is called deflagration, which is gener- 
ally performed by mixing the inflammable body with an equal 
weight of the nitrate, and projecting the mixture, in small 
portions, into a red-hot crucible. All the neutral nitrates of 
the fixed alkalies and alkaline earths, together with most of 
the neutral nitrates of the common metals, are composed of 
1 equiv. of nitric acid, and 1 of the protoxide ; hence the 
oxygen of the base is to that of the acid, as 1 to 5 ; the 
general formula is MO -f- NO 5 . 

Nitrate of Potassa (KO -f NO 5 . 101.3) is an abundant 
natural product; it is obtained from the East Indies by 
lixiviating certain soils ; in Germany and in France, it is pro- 
duced in what are termed nitre-beds. 



3 1 Salts.. — Nitrates. 

The French process consists in lixiviating old plaster rub. 
bish. Nitre also exudes from new walls. Some caverns in 
Kentucky afford nitrate of lime, from which nitre is obtained 
by adding carbonate of potassa ; it is also found under old 
buildings, and is commonly called nitre and saltpetre. 

Properties. Colorless ; has a saline and cooling taste , 
soluble in its own weight of boiling water ; crystallizes in 
six-sided prisms without any water of crystallization ; and 
fuses at 616°. 

Fulminating Powder is formed of 3 parts of nitre, 2 of dry 
subcarbonate of potassa, and 1 of sulphur. 

Exp. Heat a small quantity in the flame of a spirit lamp, and it will 
explode with considerable violence. 

Uses. Used in chemistry as an oxidizing ' agent, and in 
the formation of nitric acid. In the East Indies, it is em- 
ployed for cooling mixtures ; one ounce of nitre to five of 
water, reduces the temperature 15°. From its anti-septic 
properties, it is employed for preserving animal substances. 

In the arts, it is extensively employed in the manufacture 
of gunpowder, which consists of nitre, sulphur, and charcoal. 
In agriculture, it is used as a manure. 

Nitrate of Soda, (NaO + NO 5 . 85.45,) called by the old 
writers cubic nitre, occurs in the soils of India, and in 
Peru ; it is analogous, in chemical properties, to the prece- 
ding ; mixed with charcoal, it burns more slowly than nitre. 

Nitrate of Ammonia (H 3 N + N0 5 . 71.3) is formed by 
neutralizing dilute nitric acid by carbonate of ammonia, and 
evaporating the solution. It is decomposed by heat, and 
yields the exhilarating gas or protoxide of nitrogen. 

Nitrate of Baryta (BaO + NO 5 . 130.85) is easily pre- 
pared by digesting the native carbonate in nitric acid, 
diluted with 8 or 10 parts of water ; on evaporation, it 
crystallizes in transparent, anhydrous octohedrons , soluble 
in 12 parts of water at 60°, and 3 or 4 of boiling water. 
This salt is used as a re-agent, for preparing pure baryta, 
and mpyrotechny, to impart a green color to flame.* 

* The green fire is composed of 13 parts sulphur, 77 nitrate ol 
baryta, 5 chlorate of potassa, 2 of arsenic, and 3 of charcoal. 



Nitrates. 311 

Sitrate of Slrontia (SrO-j-NO 5 . 105.95; in prisms, 
.tnh 5 equiv. of water, = 150.95) is prepared from the carbo- 
nate of strontia, in the same manner as the preceding, and 
has similar properties ; it is used for the redjire employed at 
theatres.* 

Nitrate of Lime (CaO-f-NO 5 . 82.65) is found in old 
plaster and mortar ; very soluble and deliquescent; crystal- 
lizes in hydrated prisms. 

The Nitrau of Magnesia (MgO + NO 5 . 74.85) has simi- 
lar properties. 

Nitrate of Protoxide of Copper (CuO + NO 5 . 93.75) is 
formed by the action of nitric acid on copper ; its crystals 
are prisms containing 7 equiv. of water, of a deep blue color, 
soluble in water and alcohol, and deliquescent. 

Exp. Spread a drachm of this salt on a piece of tin foil, moisten it 
with water, fold it, and lay it on a plate ; sufficient heat will often be 
evolved to ignite the metal. 

Nitrate of Protoxide of Lead (PbO + NO 5 . 165.75) may 
be formed by digesting litharge in dilute nitric acid ; it crys- 
tallizes in anhydrous octohedrons, and has an acid re-action. 

Dinitrate of Protoxide of Lead. 2PbO -f NO 5 . 223.2 + 
54. 15 = 277.35. 

Nitrate of the Black Oxide of Mercury (Hg 2 0+NO°. 
2G4.67 ; in crystals, with 2 equiv. of Aq=282.67) is formed 
by dissolving mercury in cold dilute nitric acid. If there is 
an excess of acid, the solution by evaporation yields clear 
transparent rhombic crystals. By allowing the solution to 
stand, small cunary yellow crystals form, having the compo- 
sition of 2HgO+NO' 6 -r- HO. 

Nitrate of the Red Oxide of Mercury (2HgO+N0 5 -f-2HO 
= 290.67) is formed by heating mercury with nitric acid in 
excess. On cooling it deposits rhomboidal crystals, deliques- 
cent and ve^y soluble. When the solution is diluted it is 
decomposed, and a basic nitrate of a bright cunary color is 
precipitated, symb. 3HgO.-f N0 5 HO. If this powder is boiled 
in a large quantity of water, still another salt is formed, hav- 
ing the formula 6HgO-r-N0 5 . 

Nitrate of Oxide of Silver (AgO+NO 5 . 170.15) may be 

* Red fire consists of 40 parts of nitrate of strontia, 13 sulphur, 5 
chlorate of potassa, and 4 sulphuret of antimony, with a little powdered 
•kticoal. 



312 Salts. — Nitrates. 

formed by dissolving silver in nitric acid, diluted with 3 
parts of water ; if the silver contain copper, it will give a 
greenish hue to the solution ; if it contain gold, it will appear 
in the form of a black powder. The solution should be per* 
fectly clear and colorless.* 

Properties. The solution by evaporation deposits trans- 
parent, tabular crystals ; it is caustic, and tinges animal sub- 
stances of a deep yellow, which becomes, by exposure to 
light, deep purple or black, and is indelible. 

Heated in a silver crucible to 426°, it fuses, and when 
cast into small cylinders, forms the lunar caustic of phar- 
macy. This, when pure, is white and transparent ; but the 
common lunar caustic is dark and opaque, owing to the 
decomposition of the nitrate, by raising the temperature too 
high in its preparation, and also in consequence of copper 
and gold, which are often contained in it ; it is soluble in its 
own weight of cold, and in half its weight of boiling water. 

It is decomposed by light, leaving a black stain upon the 
skin or on paper, (see p. 68;) hence it is a very delicate test 
of animal matter, also of chlorine and hydrochloric acid, 
which latter causes a white precipitate, the chloride of silver. 

It is also decomposed by sulphur, phosphorus, charcoal, 
hydrogen, and several of the metals. 

Exp Place a few grains of this salt, with a little sulphur, and also 
with phosphorus, upon an anvil ; when struck sharply with a hammer, 
the former will detonate, and the latter explode violently. 

Exp. Dip a piece of silk into a solution of this salt, and, while moist, 
pass over it hydrogen gas ; it will at first turn black, and then become 
iridescent, from the reduction of the metal. 

Exp. Immerse in a solution of this salt a stick of phosphorus ; it will 
soon become beautifully inciusted with the metal. 

Exp. Immerse a slip of ivory in a dilute solution of the salt, till the 
ivory has acquired a bright yellow stain ; remove it to a tumbler of dis- 
tilled water, and expose it to the direct rays of the sun for two hours, 

* One of the best solvents of silver may be formed by dissolving 1 
part of nitre in 10 by weight of concentrated sulphuric acid. When 
this compound is heated to between 100° and 200° Fahr., it will dis- 
solve about one sixth of its weight of silver without acting in the least 
upon any copper, gold, lead, or iron, with which the silver may be 
combined ; hence it is very useful to detach silver from old plate. T« 
recover the silver from the solution, add common salt, and then de» 
compose the chloride thus formed by carbonate of soda. 



Nitrates — Chlorates. 313 

when it will become black, but, on rubbing it, the surface will become 
bright, resembling pure silver. 

Nitrate of Silver is the principal ingredient in indelible 
ink, and in those compounds which are used for changing 
the color of the hair. 

In all these cases, the effect depends upon the reduction of 
a part of the silver to the metallic state. 

4. Nitrites. 
According to Turner, very little is known of these salts. 

5. Chlorates. 

The salts of chloric acid are very analogous to thos<? of 
nitric acid. They are all soluble in water, and are dis- 
tinguished by the action of strong hydrochloric and sulphuric 
acids, the former disengaging chlorine, and protoxide of chlo- 
rine, and the latter chlorous acid. 

The chlorates are mostly composed of 1 equiv. of protoxide 
and 1 of acid ; hence the oxygen of the base is to that of the 
acid, as 1 to 5, or Mo -f- CIO 5 . 

None of the chlorates are found native, and those of baryta 
and potassa are the only ones which require particular notice. 

Chlorate of Potassa (KO-fClO 5 . 122.57) may^be formed 
by transmitting chlorine gas through a concentrated solution 
of pure potassa, until the alkali is completely neutralized ; the 
results are chloride of potassium and chlorate of potassa.* 

Properties. Chlorate of potassa generally occurs in four 
and six-sided crystalline scales ; colorless, and of a pearly 
lustre ; soluble in 16 times its weight of water at 60°, and in 
2£ of boiling water. It is anhydrous, and fuses at 400° or 
500° ; by increase of temperature, it yields pure oxygen gas. 

It acts very energetically upon many imflammable bodies. 

. Exp. Put 2 grains of the salt into a mortar, with 1 grain of 
sulphur. Mix them accurately, and then strike the collected mass 

* For other processes, see Turner's Chemistry. 
14 



814 Salts. — Chlorates. 

forcibly with the pestle ; a loud detonation will ensue. Charcoal wift 
produce a similar effect; or, 

Exp. Instead of the sulphur, add a grain of phosphorus, and the 
detonation will be much louder.* 

Many of the stronger acids decompose this salt. 

Exp. Mix 2 parts of sugar with 1 of chlorate of potassa, and pout 
upon it a few drops of sulphuric acid ; the decomposition will be at- 
tended by a sudden inflammation. 

Exp. Put 2 parts of this salt with 1 of phosphorus into a wine- 
glass filled with warm water, and then pour, by means of the dropping- 
tube, strong sulphuric or nitric acids directly upon the salt; the phos- 
phorus will ignite under the water, owing to the development of oxy- 
gen from the decomposition of the salt. 

Uses, It is employed in the preparation of percussion 
powder, in which this salt is substituted for nitre. 

Matches are also made by first dipping them in melted sul- 
phur, and then in a composition of chlorate of potassa, sugar, 
gum arabic, and vermilion. 

Lucifer Matches have a similar composition. 

An attempt was made in 1788 to substitute chlorate of 
potassa for nitre, in the manufacture of gunpowder; but, 
as might have been expected, on triturating the mixture, 
it exploded with violence, and destroyed several of the 
operators. 

A few grains of this salt, put into water with a few 
drops of hydrochloric acid, form a convenient bleaching 
liquor. 

Chlorate of Baryta (BaO + CIO 5 . 152.12) is prepared by 
digesting for a few minutes a concentrated solution of chlorate 
of potassa, with a slight excess of silicated hydrofluoric acid ; 
the alkali is precipitated in the form of an insoluble, double 
hydrofluate of silica nd potassa, while chloric acid remains 
in the solution. The 'iquid, after nitration, is neutralized 
by carbonate of baryta, < hich throws down the excess of 
silicated hydrofluoric acid, and chlorate of baryta remains 
in solution. 

Properties. It yields, on evapo. ^tion, crystals in the form 
of four-sided prisms, has a pungent tas^, is soluble in 4 times 
its weight of cold, and in a smaller quanu + y of warm water 
It is employed for forming chlorous acid. 



* The hands should be covered with gloves, and the mortar turned 
from the face. 



Perchlorateb — Iodates. 31 5 

6. Perchlorates. 

The neutral protosalts of perchloric acid consist of 1 
equiv. of acid and base, as is expressed by the formula 
MO -|- CIO 7 . Most of the salts are deliquescent, very solu- 
ble in water, and soluble in alcohol. When heated to red- 
ness, they yield oxygen gas and metallic chlorides ; and they 
are distinguished from the chlorates by not acquiring a yellow 
tint, on the addition of hydrochloric acid. — T. 

The salts are formed by neutralizing the base with per- 
chloric acid, excepting perchlorate of potassa, which is 
formed from the chlorate by heat and sulphuric acid. 

7. Chlorites. 

The alkaline chlorites are formed by transmitting a current 
of chlorous acid gas into a solution of the pure alkalies; they 
are remarkable for their bleaching and oxidizing properties. 

8. Hypochlorites. 

These salts may be formed by the action of chlorine gas on 
the alkaline bases ; the most important of these is the hypo- 
chlorite of lime, which is well known as a bleaching powder. 

9. Iodates. 

The salts of iodic acid are very similar in character to 
those of chloric acid ; in all the neutral protiodates, the oxy- 
gen of the base and acid is in the ratio of 1 to 5 ; the 
iodates are easily recognized by the action of de-oxidizing 
agents. Thus the sulphurous, phosphorous, hydrochloric 
and hydriodic acids deprive the iodic acid in the salt of 
its oxygen, and set the iodine at liberty. None of the 
iodates are found native ; they are all insoluble, or sparingly 
Boluble in water, excepting the iodates of the alkalies. 

Iodate of Potassa (KO-j-lO 5 . 213.45) may be obtained 



316 Salts. — Phosphates. 

by adding iodine to a concentrated, hot solution of pure 
potassa, until the alkali is completely neutralized. All the 
insoluble iodates may be procured from this salt ; thus the 
iodate of baryta may be formed by mixing chloride of 
barium with a solution of iodate of potassa. 

10. The Bromates are very similar to the chlorates and 
iodates. 

11. Phosphates. 

There are three acids of phosphorus which are isomeric — 
the phosphoric, pyrophosphoric, and mctaphosphoric ; hence 
it becomes necessary to have three corresponding families of 
salts. 

I. Phosphates. All the neutral protophosphates are solu- 
ble in water, and redden litmus paper, on which account they 
are called superphosphates. 

The Triphosphates, except those of the pure alkalies, are 
sparingly soluble, or insoluble in water, but are all dissolved 
by nitric or phosphoric acids. The phosphates and diphos- 
phates are changed by heat into pyrophosphates and meta- 
phosphates ; the phosphates of the pure alkalies are but par- 
tially decomposed by heat and combustible matter, and those 
of baryta, strontia, and lime, undergo no change ; but most of 
the phosphates of the second class of metals are resolved into 
hosphurets by those agents. 

The insoluble phosphates are decomposed when boiled 
with a strong solution of carbonate of potassa, or soda. 

Triphosphate of Potassa (3KO + P 2 5 . 212.85) is formed 
by adding caustic potassa in excess to a solution of phos- 
phoric acid. 

Diphosphate of Potassa (2K0.2HO + PSQ 5 . 165.7) is pre- 
pared by neutralizing the superphosphate of lime obtained 
from bones, with carbonate of potassa. 

Phosphate of Potassa (K0.2HO + P 2 Q 5 . 136.55) is formed 
by adding phosphoric acid to carbonate of potassa, until the 
liquid ceases to give a precipitate with chloride of barium, 
and then setting aside to crystallize. 



Phosphates. 317 

Triphosphate of Soda. 3NaO + P 2 5 . 165.3 ; in crystals, 
with 24 equiv. of water, = 381.3. This salt is prepared by 
adding pure soda to a solution of the succeeding compound, 
until the liquid feels soapy to the fingers; the solution is then 
evaporated until a pellicle forms; on cooling, the crystals 
which are deposited, are quickly re-dissolved in water, and are 
crystallized. 

Properties. Triphosphate of soda crystallizes in colorless, 
six-sided, slender prisms, which have an alkaline taste and re- 
action ; soluble in five times their weight of water at 60°, and 
in still less of hot water; the crystals undergo watery fusion 
at 170°, but are not decomposed at a red heat. The feeblest 
acid deprives the salt of ^ of its soda. 

Triphosphate of Soda and Basic Water. 2NaO.HO-|- 
P' 2 5 . 143 ; in crystals, with 24 equiv. of water. = 359. This 
salt is the most common of the phosphates, being manufac- 
tured on a large scale, by neutralizing, with carbonate of 
soda, the acid phosphate of lime, which is procured by the 
action of sulphuric acid on burned bones. 

Properties. It crystallizes in oblique rhombic prisms, 
hence called rhombic phosphate ; its crystals are always alka- 
line to test paper; effloresce in the air ; soluble in four times 
their weight of cold, and twice their weight of warm water. 

Acid Triphosphate of Soda and Basic Water (Na0.2HO 
+ P 0"\ 120.7 ; in crystals, with 2 eq. water, = 138.7) is com- 
monly called the Diphosphate of soda, and may be formed by 
adding phosphoric acid to a solution of carbonate of soda, 
until it ceases to give a precipitate with chloride of barium. 
When the solution is concentrated, it yields two different 
kinds of crystals without varying its composition. 

Phosphate of Soda and Ammonia (NaO.H 3 N-fP 2 5 . 
119.85, with 10 eq. water = 209.85) is easily prepared by 
mixing 1 equiv. of hydrochlorate of ammonia, and 2 equiv. 
of the rhombic phosphate of soda ; each being previously 
dissolved in a small quantity of boiling water. 

It is known as microcosmic salt, and is much employed as 
a flux in experiments with the blowpipe ; when heated, it 
parts with its water and ammonia. 



318 Salts. — Phosphates. 

Diphosphate of Ammonia (2H 3 N + P 2 5 . 105.7; in crys- 
tals, with 3 equiv. water, = 132.7) is prepared by adding am- 
monia to phosphoric acid until a precipitate is formed ; the 
primary form of the crystals is an oblique rhombic prism 

Phosphate of Ammonia (H 3 N-}-P 2 () 5 . 88.55 ; in crystals, 
with 3 equiv. water, = 115.55) is formed in the same manner 
as the phosphate of potassa, crystallizes in octohedrons with 
a square base, and in right square prisms. 

Bone Phosphate of Lime (8CaO -f-3P 2 5 . 442.2) exists 
in bones after calcination, and falls as a gelatinous precipitate, 
on pouring chloride of calcium into a solution of rhombic 
phosphate of soda. 

Triphosphate of Lime (3CaO -j- P 2 5 . 156.9) occurs in the 
mineral called apatite. 

Diphosphate of Lime, (2CaO -f-P 2 5 -|- 1 eq. basic water, 
= 137.4,) commonly called neutral phosphate, falls as a granu- 
lar precipitate, when the rhombic phosphate of soda is added, 
drop by drop, to chloride of calcium in excess. 

Phosphate of Lime (CaO -f- P~0 5 -|-2 eq. basic water, =. 
117.9) is commonly called the Diphosphate, from its acid re- 
action, and may be formed by dissolving either of the pre- 
ceding salts in a slight excess of phosphoric acid ; it exists in 
urine. 

Diphosphate of Magnesia. 2MgO + P 2 5 . ] 12.8. 

Triphosphate of Magnesia. 3MgO + P 2 5 . 133.5. 

Phosphate of Ammonia and Magnesia (2MgO -j- 2H 3 N -}- 
10HO-j-P 2 O 5 . 237.1) subsides as a pulverulent, granular 
precipitate from neutral alkaline solutions, containing phos- 
phoric acid, ammonia, and magnesia; it constitutes a variety 
of urinary concretions. 

Triphosphate of Oxide of Silver is formed when the 
rhombic phosphate of soda is mixed in solution with nitrate 
of silver ; it is a yellow powder when dry ; on exposure to 
light, it is speedily blackened. 

II. Pyrophosphates. The only salts of this family which 
have been studied, are those of soda and oxide of silver. 
They are thus constituted : — 



Arseniates. 319 

Dipyrophosphalz of Soda. 2NaO +P 2 5 . 62.6 + 71.4 =134. 

Dlpyropkospliate in crystals, with 10 eq. water, 90 = 224. 

Acid Dtpyroplwsphate of Soda and Basic Water. NaO, HO + P 2 0* =a 
1117. 

Pyrophosphate of Soda. NaO.P 2 3 . 31.3 -f- 71.4 = 102.7. 

Dipyrophosphatc of Oxide of Silver. 2Ag0 + P 2 5 ; 232 + 71.4 = 
303.4. 

III. Metaphosphates. The only salts of this family yet 
examined are those of soda, baryta, afnd oxide of silver. 

Metayhosphate of Soda. NaO.P 2 5 , 1 eq. Na,31.5 + leq. P^O 5 , 71.4 
= 10-2.7. 

Metaphosbhate of Baryta. BaO.P 2 5 , 1 eq. BaO, 767 + leq. P 2 5 , 
71.4 = 148.1. 

Metaphosphate of Silver. AgO.P 2 5 , 1 eq. AgO, 116-j-l eq. P 2 5 , 
71.4=187.4. 

Sub-meta phosphate of Silver. 3AgO -f2P 2 5 , 3 eq. AgO, 348+2 eq. 
P 2 5 , 142.8 = 490.8. 

12. Arseniates. 

Arsenic acid resembles the phosphoric in composition, 
and in many of its properties. The oxygen of the oxide and 
acid in their salts is as 1 to 5; salts of 2 equiv. of basic 
water are soluble in water, redden litmus paper, and are 
usually considered bisalts ; those with 1 equiv. of basic 
water, in which the oxygen of the base and acid is as 2 to 
5, are commonly called neutral arseniates; those without 
Water are described as subarseniates. This acid has a strong 
tendency to form trisalts ; some of the arseniates bear a red 
heat without decomposition, but all are decomposed when 
thus heated with charcoal, metallic arsenic being set at 
liberty. 

The soluble arseniates are easily recognized by the tests 
for arsenic. (See p. 266.) 

The insoluble arseniates are tested by boiling them in a 
strong solution of the fixed alkaline carbonates, by which 
they are deprived of their acid; the acid may then be de 
tected in the usual way. 
• The following are the principal arseniates : — 

Trinrseniate of Soda. 3NaO -f- As 2 5 , 3 eq. NaO, 93.7+ 1 eq. 
As'^O 5 , 115.4 = 209.3. 
Do. in crystals with 1 eq. water 216 = 425.3. 



320 Salts. — Ar smites. 

Diarseniate of Soda and Basic Water. 2NaO + HO -f- As 2 5 , eq. 187. 

Acid Arseniate of Soda and Basic Water. NaO -f- 2HO + As 2 5 aq. =* 
164.7. 

Triarseniate of Potassa. 3KO + As 2 5 , 3 eq. KO, 141.45 + 1 eq 
As 2 0\ 115.4 = 256.85. 

Diarseniate of Potassa. 2KO -4- As 2 5 , 2 eq. KO, 94.3 + 1 eq 
As 2 5 , 115.4 = 209.7. 

Arseniate of Potassa. KO. As 2 5 , 1 eq. KO, 47.15 -f-1 eq. As 2 5 , 
115.4 = 162.55. 

Diarseniate of Ammonia. 2H 3 N+As 2 5 , 2eq. NH 3 , 34.34-1 eq 
As 2 5 , 115.4 = 149.7. 

Arseniate of Ammonia. NH 3 , As 2 5 , 1 eq. NH 3 , 17.55 + 1 eq 
As 2 5 115.4 = 132 55 

Triarseniate of Baryta. 3BaO + As 2 5 , 3 eq. BaO, 230.1 + 1 eq 
As 2 5 , 115.4=345.5. 

Diarseniate of Baryta. 2BaO + As 2 5 , 2 eq. BaO, 153.4 + 1 eq. 
As 2 5 , 115.4 = 268.8. 

Arseniate of Byrata. BaO + As 2 5 , 1 eq. BaO, 76.7 + 1 eq. As 2 5 
115.4 = 192.1. 

Triarseniate of Lime. 3CaO + As 2 5 , 3 eq. CaO, 85.5 + 1 eq 
As 2 5 , 115.4 = 200.9. 

Diarseniate of Lime. 2CaO + As 2 5 , 2 eq. CaO, 57 + 1 eq. As 2 5 
115.4 = 172.4. 

Arseniate of Lime. CaO + As 2 5 , 1 eq. CaO, 28.5 + 1 eq. As 2 5 
115.4 = 143.9. 

Triarseniate of Lead. 3PbO + As 2 5 , 3 eq. PbO, 334.8 + 1 eq 
As 2 5 , 115.4=450.2. 

Diarseniate of Lead. 2FbO+'As 2 5 . 2 eq. PbO, 223.2+1 eq 
As 2 5 , 115.4 = 338.6. 

Triarseniate of Ox-Silver. 2AgO + As 2 5 , 3 eq. AgO, 348 + 1 cq 
As 2 0\ 115.4 = 463.4. 



13. Arsenites. 

The arsenites of potassa, soda, and ammonia, may be 
prepared by acting with those alkalies on arsenious acid. 

They are very soluble in water, and have an acid re-action. 

Most of the other arsenites are insoluble or sparingly solu- 
ble m water, but are dissolved by an excess of arsenious, 
nitric, and most other acids, with which their bases do not 
form insoluble compounds. 

They are all decomposed when heated in close vessels. 

The. soluble salts, if neutral, are characterized by forming 
a yellow arseniate of oxide of silver, when mixed with nitrate 
of silver, and a green arsenite of protoxide of copper — ■ 
Schee.le's green — with sulphate of copper. 

The arsenite of potassa is the active principle in Foicler^h 
arsenical solution. 



Chromates — Borates 321 



14. Chromates. 



The chromates may generally be known by their yellow 
■)r red color. They may be known chemically by the green 
solution of chloride of chromium, formed by boiling any 
chromate with hydrochloric acid mixed with alcohol. They 
are all decomposed by heat and combustible matter. 

Chromate of Potassa (KO -f CrO 3 . 99.15) is formed by 
heating to redness the native oxide of chromium and iron 
(chromate of iron) with nitrate of potassa, when chromic acid 
is generated, and unites with the alkali of the nitre. 

Properties. Taste cool, bitter, and disagreeable, soluble 
in boiling water, and insoluble in alcohol. 

Bichromate of Potassa (KO-j-2CrQ 3 . 151.15) is of great 
importance in dyeing. It is prepared by acidulating the 
neutral chromate with sulphuric, or, still better, with acetic 
acid, and allowing the solution to crystallize by spontaneous 
evaporation. 

Properties. When slowly formed, four-sided rhombic 
prisms are deposited, which are anhydrous, and of a rich 
red color ; soluble in 10 times their weight of water at 60° 
and the solution reddens litmus. 

The insoluble chromates, such as those of baryta, zinc., 
lead, mercury, and silver, are prepared by mixing the soluble 
salts of those bases with a solution of chromate of potassa. 

Chromate of Lead. PbO + CrO 3 . 1G3.6. TJiis is the 
yellow chromate, and is extensively used as a pigment. 
Chromate of oxide of zinc may be used for the same purpose. 

15. Borates. 

The boracic is a feeble acid, and neutralizes imperfectly ; 
hence the borates, such as soda, potassa, and ammonia, have 
an alkaline re-action ; hence, also, the more powerful acids 
separate the alkali from boracic acid, although, at a red heat, 
boracic acid, owing to its fixed nature, decomposes every salt 
whose acid i? volatile. The borates of the alkalies are solu 
14* 



&22 Salts. — -Carbonates. 

ble in water, but most of the other borates are sparingly 
soluble ; they are not decomposed by heat, though remark- 
able for their fusibility. They are distinguished by the 
following character : — 

By digesting any borate in an excess of strong sulphuric 
acid, evaporating to dryness, and boiling the residue in 
strong alcohol, the solution will burn with a green flame. 

Biborate of Soda, (2B0 3 -f NaO. 191.1 ; in crystals, with 
10 equiv. of water, ±= 101.01,) commonly called borax, oc- 
curs native in certain lakes in Thibet. It is imported from 
India under the name of tincal, which, after purification 
constitutes the refined borax of commerce. 

Properties. It crystallizes in hexahedral prisms. The 
crystals are efflorescent ; when heated, they lose their water 
of crystallization, fuse, and form, on cooling, a crystalline 
mass, called glass of borax. 

Borax is much used as a flux for welding iron and steel 

Boracite is a biborate of magnesia. 

A new biborate of soda has been lately described; better 
as a flux, for the use of jewellers, than the preceding. 

16. Carbonates. 

The carbonates are distinguished from all other salts, by 
berng decomposed with effervescence, owing to the escape 
of carbonic acid gas, by nearly all acids. 

All thexiarbonates, except those of potassa, soda, and lithia, 
are decomposed by heat ; and all, except those of potassa, 
soda, and ammonia, are of sparing solubility in pure water 
but all are soluble in excess of carbonic acid. Several of 
them occur native. 

Carbonate of Potassa (KO-f-CO 2 . 69.27) is procured by 
lixiviating the ashes of land plants, and boiling the lye — a 
process which is performed on a large scale in Russia, ana 
in this country. This is the impure carbonate of commerce, 
known by the names potash and pearlash, and is of great utili- 
ty in the arts, especially in the manufacture of soap and glass 
As thus prepared, it always contains other compounds, such 



Carbonates. 323 

es sulphate of potassa, and chloride of potassium. For 
chemical purposes, it is obtained by heating cream of tartar 
to redness, when the acid is decomposed, and a pure car- 
bonate of potassa mixed with charcoal remains. The char- 
coal is removed by solution in water, and evaporation. 

Properties. Taste strongly alkaline, and slightly caustic; 
changes the vegetable purple colors to green; soluble in less 
than an equal weight of water at 60°; deliquesces on ex- 
posure to the air ; is insoluble in pure alcohol, and fuses at 
a full red heat, but undergoes no other change. 

Bicarbonate of Potassa (KQ-J-2CQ 2 . 91.39; in crystals, 
with 1 equiv. water, = 100.39) is made by transmitting a 
current of carbonic acid gas through a solution of the car- 
bonate. This salt is milder than the carbonate, into which 
it is converted by a low red heat It does not deliquesce on 
exposure, and requires fcur times its weight of water at 60° 
for solution. 

Carbonate of Soda (NaQ+CQ 2 . 53.42; in crystals, with 
10 equiv. water, — 143.42) was formerly obtained from the 
ashes of several species of sea-weed, but it is now obtained 
from common salt, {chloride of sodium.) The salt being first 
converted into sulphate of soda by the action of sulphuric acid 
and heat, is acted upon by chalk heated with small coal. , The 
fused mass is called black ash, and from it the pure carbonate 
is obtained by dissolving in boiling water and crystallizing. 

Properties. Crystallizes in rhombic prisms ; effloresces, 
and dissolves in its water of crystallization when heated, and 
becomes anhydrous by continued heat; soluble in about 2 
parts of cold, and in less than its weight of boiling water. 

Bicarbonate of Soda (NaO+2C0 3 . 75.54; in crystals, 
with 1 equiv. water, = 84.54) is formed by the same process 
as the bicarbonate of potassa, and. like that salt, is much 
iTiilder than the carbonate. 

Sesquicarbonate of Soda (2NaO+3C0 2 . 4HO. 164.96) 
is found native in Africa, on the banks of soda lakes, and is 
called trona. 

Carbonate of Ammonia (H 3 N+CO\ 39.27) is obtained 
by mixing dry carbonic acid over mercury, with twice its 
volume of ammoniacal gas. It is a dry, white powder, and 



324 Salts. — Carbonates. 

has an alkaline re-action ; its odor is pungent, resembling 
ammonia. 

Bicarbonate of Ammonia (H 3 N.2HO + 2C0 2 . 79.39) is 

obtained by transmitting a current of carbonic acid gas 
through a solution of carbonate of ammonia, and evaporating 
the solution by gentle heat. It is deposited in right rhom- 
bic prisms ; inodorous, and nearly tasteless. 

Sesquicarbonate of Ammonia (2H3N.2H0 2 + SCO 2 , 
118.66) is prepared by heating 1 part of hydrochlorate of 
ammonia, mixed with 1J of carbonate of lime, carefully 
dried. 

The chloride of calcium remains in the retort, and this 
salt is sublimed; it is hard, compact, translucent, of a crys- 
talline texture, and ammoniacal odor. 

Carbonate of Baryta (BaO + CO 2 . 98.82) occurs native 
in the mineral Witherite. It may be prepared by mixing a 
soluble salt of baryta with any of the alkaline carbonates. 

Properties. This salt is anhydrous, very insoluble, and 
highly poisonous. 

Carbonate of Strontia (SrO + CO 2 . 73.92) is known by 
the name of strontianite ; it may be prepared in the same 
manner as carbonate of baryta ; it is soluble in excess of 
carbonic acid. 

Carbonate of Lime (Ca-f-CO 2 . 50.62) is a very abundant 
natural production, occurring under a great variety of forms, 
such as limestone, marble, chalk, Iceland spar, etc. ; often 
in regular crystals. Carbonic acid and lime have a strong 
affinity for each other ; and hence moist lime, or lime in so- 
lution, when exposed to the air, absorbs the acid contained 
in the atmosphere, and carbonate of lime is formed. It is 
sparingly soluble in water, but soluble in excess of carbonic 
acid ; the crust formed on the top of lime water is car- 
bonate of lime. 

Carbonate of Magnesia (MgO + CO 2 . 42.82; in crystals, 
with 3 equiv. of water, = 69.82) is found native in the mine- 
ral called magnesite, which is nearly pure anhydrous car' 
vonate of magnesia. It is obtained in minute, transparent 



Carbonates \Sttb 

hexagonal prisms, when a solution of the bicarbonate evapo- 
rates slowly in an open vessel ; the crystals lose their water, 
and become opaque by a very gentle heat, and even in dry 
air, at 60°. They are decomposed by water. 

A Carbonate of Magnesia, consisting of 4 equiv. of water, 
3 of acid, and 4 of magnesia, falls as a white powder when 
carbonate of potassa is added to a hot solution of sulphate 
of magnesia; this salt is very insoluble, requiring 9000 parts 
of hot water for solution. 

Carbonate of Protoxide of Iron (FeO + CO 2 . 58.12) is a 
very abundant natural production, occurring either in masses, 
or in rhombohedrons. It exists also in most of the cha- 
lybeate mineral waters. It may be formed by mixing an 
alkaline carbonate with sulphate of protoxide of iron. It 
acts as a tonic upon the animal system. 

Dicarbonate of Protoxide of Copper (2CuO + Co 2 . 101.32) 
is found native as a hydrate, in the mineral called malachite, 
of a beautiful green color. 

It may be obtained by precipitation from a hot solution of 
sulphate of protoxide of copper, by carbonate of soda or po- 
tassa ; this is the mineral green of painters. 

When the hydrate is boiled for a long time in water, it 
loses both carbonic acid and combined water, and the color 
changes to a brown. 

The blue copper ore, and the blue pigment called verditer* 
have a similar composition. 

Carbonate of Protoxide of Lead (PbO-f- CO^. 133.72) is 
the white lead of painters. It occurs native in white pris- 
matic crystals. As an article of commerce, it is prepared 
fiom the subacetate by a current of carbonic acid; also by 



* Refiners' Verditer, made by silver refiners, is composed of 3 equiv. 
of oxide and 4 of carbonic acid. 

A very good verditer is formed by adding a quantity of lime to ni 
trate of copper sufficient to throw down the oxide. The green precip- 
itate must be washed, and nearly dried upon a strainer. If it is then 
mixed with 10 per cent, of fresh lime, the color will become blue. It 
must now be dried, and is then fit for use, 



326 Salts. — Double Carbonates — Silicates. 

exposing metallic lead in minute division to air and moistuie, 
or by the action of the vapor of vinegar on thin sheets of 
.ead. 

Dicarbonate of Peroxide of Mercury, 2Hg0 2 -|- CO-, 
458.12. When a solution of the nitrate of peroxide o^ 
mercury is decomposed by carbonate of soda, this salt falls 
as an ochre-yellow precipitate. 



17. Double Carbonates 

The most remarkable of these salts is the double carbonate 
of lime and magnesia, (MgO.C0 2 -j-CaO.C0 2 . 93.44,) form- 
ing the minerals called dolomite, bitter spar, and pearl spar. 

The rock called magnesian limestone is an impure variety 
of dolomite. 

Barytocalcite is a double carbonate of baryta and lime, 
CaO.C0 2 -f BaO.CO 2 . 149.44. 

Carbonate of Soda, fused with the carbonate of baryta, 
strontia, or lime, in the ratio of their equiv., yields crystal- 
line, definite compounds. In the same manner, also, sulphate 
of soda, heated with the above carbonates, yields double 
salts, which are very similar. 

18. Silicates, 

Silicic Acid is one of the most powerful acids. The salts 
which it forms, although very numerous and important com- 
pounds, have not hitherto been fully investigated. The sili 
cates are remarkable for their great variety of composition : 
they are composed of from 1 equiv. of base and 6 of silicic 
acid to 1 of acid and 3 of base. Those most frequently met 
with are, — 

1. Simple Silicates, or those composed of 1 equiv. of base 
and 1 of silicic acid. These are a very numerous class of 
natural compounds, as, silicate of manganese, zinc, glucina, 
cerium, zirconia, iron, &c. 

2. Bisilicates, in which 2 equiv. of silicic acid are com* 



Silicates. 327 

bined with 1 of base. There are many native compounds 
of tnis order : tabular spar is a bisilicate of lime ; bottle 
glass is another example. 

3. Trisilicates, in which 3 equiv. of silicic acid are united 
to 1 of base. The most important of the trisilicates is plas 
tic clay, which is a trisilicate of alumina. 

4. Quadrisilicates, which are principally artificial com- 
pounds, among which are crown glass, French window glass, 
flint glass, and enamel. 

In addition, it should be remarked, that there are a very 
great number of simple minerals, which are composed as 
above, or by the union of silicic acid with other acids and 
with bases. In fact, the greater portion of the crust of the 
globe is composed of silicates. The soils, rocks, and 
mountains, are but masses of silicates. 

The silicates are all fusible before the compound blow- 
pipe, and all, except those of magnesia and alumina, in a 
forge fire. Those of 2 or more bases are most easily fused; 
and those of fusible bases are more easily melted than those 
whose bases are more refractory. 

In the separation of the metals from their ores, such mat 
ters are added as will form with the earthy parts of the ores 
fusible silicates. These float like glass on the surface of the 
reduced metal, and are easily removed. 

All kinds of glass are formed by heating siliceous sand 
with alkaline carbonates. When heat is applied, the alkali 
melts, and the sand (silicic acid) combines with the alkali, 
while the carbonic acid escapes in the form of a gas, causing 
the mass to swell to twice its former bulk. When the car- 
bonic acid all escapes, the mass subsides, and is called frit. 

1 his is then put into a refractory vessel, and placed in a 
furnace, where it is heated until it is melted and becomes 
glass. (See page 221.) 

The silicates are all insoluble, excepting those of potassa 
and coda. Those compounds formed by the union of 1 or 

2 equiv. of silicic acid are more soluble than those of 3 or 
4. The double silicates of these alkalies, that is, the union 



328 Salts. — Hydro-Salts. 

of another acid or base, renders the compounds still leaa 
soluble. 

The silicate of alumina and soda, which is combined wit I, 
sulphuret of sodium in lapis lazuli is used by painters, undei 
the name of ultramarine, and is a very important compound. 

The silicates are the most important chemical com- 
pounds ; forming, as they do, almost the entire mass of the 
soil in every country, their influence upon vegetation is con- 
stant and universal. To the agriculturist they are com- 
pounds of great interest, and should be made the subjects 
of intense study. 

Section 3. 

ORDER II. — HYDRO-SALTS. 

This order includes those salts the acid or base of which 
contains hydrogen. The salts formerly called muriates or 
hydro chlorates of metallic oxides, are now generally de- 
scribed as chlorides of those metals, and also the salts of 
hydriodic and most other hydracids. The only salts which 
are included in this order are formed by the hydracids with 
ammonia and pliosphureted hydrogen. 

Hydrochlor ate of Ammonia. H 3 N -f- HCL. 53.57. This 
is the sal ammoniac of commerce, and was formerly imported 
from Egypt, where it was prepared from the soot of camels' 
dung by sublimation; but it is now formed by several pro- 
cesses. The most usual is to decompose the sulphate of am- 
monia* by the chloride of sodium or magnesium. 

It occurs native, in masses and in crystals, in the vicinity 
of volcanoes. 

Process. It may be produced directly, by introducing 
liquid ammonia into one retort, (see Fig. 54, p. 113,) and 
HCL into the other, and apply heat. As the two gases pass 



* This sulphate is obtained by digesting with gypsum the impure 
carbonate of ammonia, procured from the destructive distillation of 
oones and other animal substances, so as to form an insoluble carbonate 
of lime and a soluble sulphate of ammonia. 



Hydro-Salts 320 

:nto the receiver, a white cloud appears, which is hydrochlo- 
rate of ammonia in fine powder. 

Properties. This salt has a pungent, saline taste, and is 
insoluble in water and in alcohol ; it sublimes at a tempera- 
ture below that of ignition, without fusion or decomposi- 
tion. 

Uses. Used in the arts for a variety of purposes, in tin- 
ning copper, to prevent oxidation, and by dyers. 

When dissolved in nitric acid, it forms the aqua rcgia, 
which is employed for dissolving gold, instead of nitro- 
hydrochloric acid. 

Hydriodale of Ammonia (H 3 N.HI. 144.45) is a white powder, very 
soluble and deliquescent. 

Hydrohromats of Ammonia (H 3 N.HBr. 96.55) is a white anhy 
drous salt. 

Hydrofluate of Ammonia. H 3 N. HI. 36.83. See Turner, 5th edit, 
p. 469. 

Hydrosulphate of Ammonia (H 3 N-{-KS. 34.25) is 
formed by heating a mixture of 1 part of sulphur, 2 of sal- 
ammoniac, and 2 of unslacked lime. It is used as a re- 
agent, and for this purpose it is formed by saturating a 
solution of ammonia with hydrosulphuric acid. 

Hydrocyanate of Ammonia. H 3 N + HC 2 N. 44.54. 

Hydrosulpliocyanate of Ammonia. H 3 N -\- HCyS 2 . 76.74. 

Triftuoborate of Ammonia. 3H 3 N + BF 3 . 118.39. 

Difluoborate of Ammonia. 2H 3 N + BF 3 . 101.24 

Fluoborate of Ammonia. H 3 N + BF 3 . 84.09. 

Fluosilicate of Ammonia. H 3 N + SiF. 43.33. 

Carbosulphate of Ammonia. H 3 N -\- CS 2 . 55.47.* 

Salts of Phosphureted Hydrogen. 

Phosplmreted Hydrogen resembles ammonia in composi- 
tion, and in some of its properties; it is a feeble alkaline 
base, and combines with some of the hydracids. The salt 

» See Turner, 5th edit. p. 469. 



330 Salts. — Sulphur-Salts. 

best known is the hydriodate of phosphureted hydrogen, 
which is composed of 127.3 parts or 1 eq. acid, and 34.4 
parts or 1 eq. base, and crystallizes in cubes. 



Section 4. 

ORDER III. — SULPHUR-SALTS. 

The sulphur-salts are double sulphur ets, just as the oxy. 
salts are double oxides. 

The sulphur-salts, with two metals, are so constituted, that 
if the sulphur in each were replaced by an equivalent quan-> 
tity of oxygen, it would form an oxy-salt. 

The close analogy between the two orders of salts appear? 
a.so from the fact, that hydrosulphuric and hydrosulphocy- 
anic acids unite ooth with ammonia and sulphur bases. 

The principal sulphur bases are the prbtosulphurets of 
potassium, sodium, lithium, barium, strontium, calcium, 
magnesium, and the hydrosulphate of ammonia; and the 
sulphur acids are the sulphurets of arsenic, antimony, tung- 
sten, molybdenum, tellurium, tin, and gold, together with 
hydrosulphuric acid, bisulphuret of carbon, and sulphuret of 
selenium. 

The sulphur-safes are divided into families which contain 
the same sulphur acid ; the generic name of each family is 
formed from the sulphur acid terminated with sulphuret ; 
thus the salts which contain persulphuret of arsenic or 
hydrosulphuric acid, as the sulphur acid, are termed arsenio* 
^ulphurets and hydro sulphur ets, and a salt composed of those 
sulphui acids, with sulphuret of potassium, is termed arsenio' 
sulphuret, and hydro sulphuret of sulphuret of potassium, or 
simply hydro sulphuret of potassium .* 



* Dr. Hare has adopted a method of naming the sulphur-salts 
founded on the nomenclature of the oxy-salts. He calls the electro- 
negative sulphuret an acid, and forms its name by changing the termi- 
nation of the element with which the sulphur is combined into ic, and 



Sulphur ets. 331 



1. Hydro-sulphurets. 

The salts of this family have hydrosulphuric acid for their 
idectro-negative ingredient ; most of them are soluble in 
water, are decomposed by exposure to the air and by acids. 

Ilydro-sulphuret of Potassium. KS-j-HS. 72.35. 

The anhydrous salt may be obtained by heating to low 
redness anhydrous carbonate of potassa in a tubulated retort, 
hrough which a current of hydrosulphuric acid is transmit- 
ted. It forms, when cold, a white, crystalline solid. The 
hydrous salt has an acrid, alkaline, and bitter taste. 

Ilydro-sulphuret of Sodium. NaS -f- HS. 50.5. 

Hydro-sulphuret of Lithium. LS -\- HS. 43.2. 

Hydro-sulphuret of Barium (BaS -\~ HS* 101.9) is formed 
by the action of hydrosulphuric acid on a solution of baryta, 
excluded from the air. It crystallizes in. four-sided prisms, 
and is very soluble. 

Hydro-sulphuret of Strontium. SrS -|- HS. Eq. 77. 

Hydro-sulphuret of Calcium. CaS -f- HS. Eq. 53.7. 

Hydro-sulphuret of Magnesium. MgS-{-HS. Eq. 45.9. 

2. Hydro-sulphocyanides. 

The acid of these salts is the hydrosulphocyanuric acid. 

Hydro-sulpkocyanide of Potassium (KS-|-HCyS 2 . 114.84) 
is a white, crystalline solid, soluble in water and in alcohol. 

II ydro-sulpho cyanide of Hydrosulphdte of Ammonia 
(H 3 N + HS) + (HCyS 2 . 93.84) exists in long, brilliant crys- 
tals, of a lemon-yellow color. 

3. Carbo-sulphurets. 

The acid of this family is the bisulphuret of carbon. 

Carbo-sulpkuret of Potassium (KS + CS 2 . 93.57) is pre- 
parer, by agitating bisulphuret of carbon with a strong alco- 
holic solution of protosulphuret of potassium. The liquid, 
when set at rest, separates into three layers, the lowest of 
which is the carbo-sulphuret of potassium. On evaporation, 

prefixing sulpk or suJpho. Thus, persulphuret of arsenic he calls sulph- 
arsenic acid, and its sulphur salts, sulpharseniates. Hydrosulphuric acid 
he denominates sidphydric acid y and its salts sulphydrates ; so of the rest. 



332 Salts, — Molybdo-sulphurets. 

a deliquescent, yellow, crystalline salt is deposited, sparingly 
soluble in alcohol. 

The Carbo-sulphuret of Sodium (NaS + CS 2 . 77.72) and 
the Carbo-sulphuret of Lithium (LS -f- CS 2 . 64.42) are simi- 
lar to the preceding. 

Carbo-sulphuret of the Hydrosulphate of Ammonia (H 3 N 
HS-f-CS 2 . 72.57) is a very volatile salt, and must be kepi 
in bottles tightly corked. Exposed to the air, it absorbs 
water and becomes red.* 



4. Arsenio-sulphurets. 

Each of the three sulphurets of arsenic is capable of acting 
as a sulphur acid ; giving rise to three distinct families of 
sulphur salts, arsejiio-protosulphurets, arsenio-ses qui sulphurets , 
and arsenio-per sulphurets. The persulphuret of arsenic is 
the most powerful of these acids. The arsenio-persulphurets 
of the alkalies and alkaline earths, are very soluble in water, 
have a lemon-yellow color when anhydrous, but colorless 
when combined with water of crystallization, or in solution ; 
but those of the second class of metals are generally in- 
soluble. 

5. Molybdo-sulphurets. 

The acid in this family is the ter sulphur et of molybdenum. 
The most remarkable of these salts is 

Molybdtt-sulpnuret of Potassium, (KS -f- MoS 3 . 151.25,) 
which is formed by decomposing a solution of molybdate of 
potassa with hydrosulphuric acid ; on evaporation, beautifu* 
crystals with <bur and eight sides are deposited. Berzelius de- 
scribes this compound as the most beautiful which chemistry 
can produce. The crystals, by transmitted light, are ruby- 
red, and their surfaces, while moist, and also the solution 
which yields them, shine like the wings of certain insects, 
with a metallic lustre, of a rich green tint. 



* The carbo-sulphuret of barium, (BaS -f- CS 2 . 123.12,) the caibo-suh 
phurct of strontium, (SrS-j-CS 2 . 98.22,) and the carbo-sulphuret of calcium , 
(CaS -f- CS 2 . 74.92,) may be obtained by acting on bisulphuret of car- 
bon with a solution of the protosulphurets of these metals. The solu- 
tions are orange or brown, and the crystals, when dry, are of a citron» 
vellow color. Carbo-sulphuret of magnesium. MgS + CS 2 . 67.12. 



Haloid Salts. 



6. Antimonio-sulphurets. 



The acid of this family is the sesquisulphuret of antimony, 
and the only salt examined is the antimonio-sulphuret of po- 
tassium., which may be formed by mixing 2 parts of car- 
bonate ofpotassa, 4 of sesquisulphuret of antimony, and 1 of 
sulphur, and fusing the mixture. 

7. TuNGSTO-SULPHURETS. 

The best known of this family is potassium. When a 
solution of tungstate of potassa is decomposed by hydrosul- 
phuric acid, and the solution evaporates, anhydrous, quadri- 
lateral, flat prisms are deposited, of a pale-red color, whicn is 
the tungstosulphuret of potassium. This salt unites with 
tungstate of potassa as a double salt. 



Section 5. 

ORDER IV. — HALOID SALTS. 

This order includes substances composed, like the pre- 
ceding salts, of bi-elementary compounds, one or both of 
which are analogous to sea-salt in composition. The haloid 
acids belong generally to the electro-negative, and the haloid 
bases to the electro-positive metals. 

The following are the principal groups or families : — 

1. Hydrar go-chlorides. The haloid acid is the bichloride 
of mercury ; they are obtained by mixing their ingredients in 
the ratio of combination, and setting aside the solution to 
crystallize. 

2. Auro-chlorides. The acid in this family is the ter- 
chloride of gold ; they are prepared like the preceding; most 
of them have an orange, or a yellow, color. 

3. P latino-chlorides. The haloid acius in this family are 
the protochloride and bichloride of platinum. 

• 4. Palladio-chlorides are salts in which the chlorides of 
palladium act as haloid acids, combining with many of the 
metallic chlorides. 



334 Salts. — Haloid Salts. 

5. Rhodio-cJiIorides are formed by the action of sesqui- 
chloride of rhodium on the chlorides of potassium and so- 
dium. 

6. The Chlorides of Iridium and Osmium are the haloid 
acids of the iridio-chlorides and the osmio-chlorides. 

7. Ozy -chlorides. This family embraces a large number 
of compounds, in which a metallic oxide is united with a 
chloride, generally of the same metal, but often of other 
metals. These salts are commonly termed submuriates, on 
the supposition that they consist of hydrochloric acid, com- 
bined with two or more equivalents of an oxide. 

Oxy- chlorides of Iron. When the crystallized protochloride of iron ig 
strongly heated in close vessels, a deep green oxy-chloride, in scaly 
crystals, is formed. 

Oxy-chloride of Copper constitutes the paint called Brunswick green, 
and is prepared by exposing metallic copper to hydrochloric acid. This 
is the compound formed by the action of sea-water on the copper of 
vessels. 

Oxy-chloride of Lead may be formed by adding pure ammonia to a 
hot solution of chloride of lead; another oxy-chloride — the pigment 
called patent yellow — is prepared by the action of moist sea-salt on 
litharge. 

8. Chlorides with Ammonia. The perchlorides of tin and 
some other metals absorb ammonia at common temperatures, 
and most of the other chlorides absorb it when gently heated; 
but most of these compounds lose their ammonia, on exposure 
to the air, and nearly all, by heat. 

9. Chlorides with Phosphureted Hydrogen. These are 
rery similar to those with ammonia, and are not of sufficient 
importance to be inserted in this place. 

10. Double Iodides. These compounds have not yet been 
closely studied, but the iodides probably form with each other 
an extensive family of salts. 

The most important are the 

Platino-biniodide of Potassium, prepared by digesting an excess of 
biniodide of platinum in a concentrated solution of iodide of potassium, 
and the Platino-biniodirlp nf hydrogen, which is prepared by acting on 
biniodide of pialmum with a cold dilute solution of hydriodic acid. 

11. Oxy-iodides. The best known of this family are 
those formed by the oxide and iodide of lead. 

The double bromides have not yet been studied. 



m 



Organic Chemistry. 335 

12. Double Fluorides. There are several extensive fami- 
lies of these salts, in which the fluorides of boron, silicon, 
titanium, and other electro-negative metals, are the acids ; 
and the fluorides of the electro-positive metals are the bases. 

13. Double Cyanides and Ferro-cyanides. The double 
cyanides constitute a large and important family of salts, 
of which the principal are the ferro-cyanides, ferro-sesqui- 
cyanides, zinco-cyanides, cobalto-cyanides, nicco-cyanides, 
and cupro-cyanides, in which the proto-cyanide of iron, 
sesqui-cyanide of iron, cyanide of zinc, cobalt, nickel, and 
copper, are the electro-negative cyanides. (See Turner's 
Elements, p. 487.) 



CHAPTER IV. 

ORGANIC CHEMISTRY. 

Organic chemistry treats of those substances which are of 
animal or vegetable origin, and which are therefore called 
organic. Organic bodies differ from inorganic compounds in 
several particulars. 

1. Of the fifty-seven or fifty-eight simple substances, only 
four, carbon, hydrogen, oxygen, and nitrogen, enter in any con- 
siderable quantities into the composition of organic compounds. 
In addition to these four elements, which are called organic, 
a few other constituents are found, as iron, silicon, potassium, 
sulphur, phosphorus, &c, but these substances exist in small 
quantities. 

2. Organic compounds differ from inorganic in the greater 
nurrW of atoms of which they are composed. Thus olive 
oil contains 270 simple atoms, spermacetti 458, and albu- 
men 883, hence their composition is much more complex than 
inorganic compounds. 

3. A third characteristic of organic substances is the fa- 
cility with which they may be decomposed, and especially in 



336 Organic Chemistry. 

being, without exception, decomposed by a red heat, and often 
by a lower temperature ; if heated in the open air, they are 
converted chiefly into water and carbonic acid. 

4. With a few exceptions, organic bodies cannot be formed 
artificially, by the direct union of their elements. They are 
formed under the influence of vitality. There are, however, 
three classes into which they may be divided in respect to 
their origin. 

The first class includes those bodies which are the elements 
of an organized and living being. They are formed under 
the influence of life, and, while connected with the animal 01 
plant, do not obey the ordinary laws of affinity ; such are 
the animal and vegetable tissues, the blood, &c. They are 
organized, rather than organic bodies, and yield to affinity 
only when life is extinct. Their composition cannot be ef- 
fected by any chemical reactions, or explained by any chemi- 
cal formula. They are the products of life. 

The second class includes such substances as organized 
bodies secrete, or as are produced from the elements which 
nourish organized bodies ; such are sugar, starch, albumen, 
oils, resins, gums, &c. 

The third class includes those bodies which are formed 
from the decomposition of the two preceding classes, and are 
very numerous. 

Many of the second and third classes of compounds may 
be formed artificially by ordinary affinity, or by a force 
called catalitic. The third class resemble, in many respects, 
inorganic compounds, but are distinguished from them still 
by their greater complexity of composition. 

Catalitic force. Organic compounds manifest a strong ten- 
dency to decomposition, when exposed to tiio air or to the in- 
fluence of chemical agents. The more complex bodies are 
thereby easily reduced to those more simple. Thus, when 
yeast is added to sugar, the latter is converted into carbonic 
acid and alcohol. The yeast acts by its presence, and is 
called the catalitic agent. This agent must be in a state of 



Analysis of Organic Compounds. 



337 



decomposition in order to induce a similar state in the other 
body. The law of catalysis is, that molecules in motion im- 
part their motion to the molecules of other bodies with which 
they are brought in contact. 

Analysis of Organic Compounds. 

The elementary analysis of an organic compound is effected 
by burning the substance with oxide of copper. This oxide 
readily yields its oxygen to the carbon and hydrogen of the 
substance, forming carbonic acid with the former, and water 
with the latter. These new compounds are collected, and 
from their weight may be known the weight of the carbon 
and of the hydrogen. * 

The loss of oxygen in the oxide of copper is also noted, 
and compared with the quantity in the carbonic acid and 
water. The excess of the latter over the former, is the 
amount derived from the substance under examination ; and, 
if there be no such excess, it is inferred that there was none 
in the substance. 

Although this process is very simple, it requires a special 
apparatus, and many specific directions to insure accurate 
results. The following is a general description of the appa- 
ratus. For more minute details the student is referred to 
larger works, and such as treat of analytical processes, such 
as those of Liebig, Rose and others. 

The apparatus consists of a glass tube, free from lead, 14 
inches in length, and half an inch in diameter, drawn to a 



Fig. 108. 




15 



838 



Organic Chemistry. 



point, and sealed at one extremity, a, Fig. 108, and open 
at the other. . This tube is then filled three- fourths full 
of pure oxide of copper that has just been ignited in a 
crucible, intimately mixed with a few grains of the body to 
be examined, (suppose it to be sugar,) in a porcelain mortar, 
a little pure oxide being first put into the sealed end. The 
tube is then filled within one inch of its open end with pure 
oxide. By this process the mixture will absorb some mois- 
ture from the air, which must be expelled. To abstract this 
moisture, a small tube filled with dry chloride of calcium is 
inserted through a cork in the open extremity of the com- 
bustion tube c, while the other end of the small tube is con- 
nected with an exhausting syringe b. The tube containing 
the mixture is then placed in sand heated to 250°, and the 
air exhausted, and allowed to pass in several times, when all 
the moisture will be taken out of the mixture and absorbed 
by the chloride. The tube is then placed in a furnace made 
of sheet-iron, (B, Fig. 109,) and the open extremity of it con- 
nected with a tube A, containing fragments of dry chloride of 
calcium, for the purpose of condensing the water generated 
by the combustion. Connected with A, by a piece of India- 
rubber tube, is a glass instrument, D, consisting of 5 bulbs, 
connected together as in Fig. 109, the 3 lower a nearly filled 
with caustic potassa in solution, the weight of which must be 
accurately determined. To ascertain whether all the joints 
are tight, a few bubbles of air are drawn through the open 
end of the potash tube, and if the liquid remains raised a lit- 
tle above the level on the other side, everything is prepared 
for the next stage of the process, which is to heat the tube to 
redness, with ignited charcoal, 7i, first near to A, and then ex- 
tend it slowly towards the other extremity by means of a 
screen which is made to slide along, as in Fig. After the 

Fisr. 109. 




Analysis of Organic Compounds. 339 

combustion is completed, the combustion tube is broken off, 
and the products are weighed. The water will be in the 
tube A, and is determined by the increase of the weight of 
the chloride ; by this the quantity of hydrogen in the sub- 
stance is found. The carbon is in the form of carbonic acid, 
united to the potassa a. and the amount of it is easily deter- 
mined. By this process the quantity of hydrogen and car- 
bon are very accurately ascertained. 

Some organic substances, as volatile liquids, are prepa- 
red for combustion in a different 
manner. A bulb, b, with a nar- Fi £« 110, 

row neck, Fig. 110, is carefully 
weighed, then filled with the li- 
quid and hermetically sealed, and 
weighed a^ain, to determine the 
quantity of liquid. The end, a, 
is then broken off and inserted in 
the combustion tube, which is filled 
with oxide of copper, and arranged 
as in Fig. 109. By heating the 
bulb, the liquid is volatilized, and 
passing through the oxide of cop- 
per, is decomposed. The products are collected, and the 
composition determined, in the same manner as in the pre- 
ceding analysis. 

In the analysis of bodies, such as fats, containing much 
hydrogen, chromate of lead is used instead of oxide of cop- 
per. To ascertain the quantity of nitrogen present, the sub- 
stance is heated with excess of carbonate of potassa, when all 
the nitrogen will be given off in the form of ammonia, and 
the amount thus accurately ascertained. 

To determine the quantity of chlorine, the vapor is passed 
over quicklime heated to redness, chloride of calcium is 
formed, and this is decomposed by nitrate of silver. From 
the weight of the chloride of silver, the quantity of chlorine 
is easily deduced. Some other substances are found in 
organic bodies, in small quantities, such as sulphur and 
metallic oxides. 




340 Organic Chemistry. 

Constitution and Classification of Organic bodies. 

I. Theory of Compound Radicals. In inorganic chemistry 
simple elements, as we have seen, are united two and two { 
or in a binary arrangement ; thus, oxygen and sulphur unite 
to form SO 3 , oxygen and potassium unite to form potassa, and 
then sulphuric acid and potassa unite to form sulphate of 
potassa, (S0 3 +KO) the acid being regarded as negative and 
the alkali as positive. It has been supposed that this binary 
arrangement applies to organic compounds, but as these are 
composed often of several simple elements, it is necessary to 
regard the compound of two or more elements as possessing 
the properties of a simple body. Thus cyanogen, composed 
of NC 2 , performs, in its various combinations, the part of an 
element. So when crystallized oxalate of ammonia, repre- 
sented by the formula NH 3 .HO.C 2 .0 3 . is distilled, a white 
tasteless powder is obtained, which has the composition NH 2 . 
C 2 2 , or it is oxalate of ammonia deprived of 3 equivalents 
of water ; it is called oxamide. On heating this in contact 
with potassa, it takes up 3 atoms of water, and is converted 
into oxalate of ammonia ; hence it is inferred that there ex- 
ists a compound of 1 equiv. of N. and 2 equiv. of H — NH 2 . 
This body has never been isolated, but has been supposed to 
act as a simple element, and has been called amide or ammi- 
dogen ; symbol. Ad. This body combines with potassium, 
and forms potassamide, NH 2 K, and also with several other 
bodies. 

In the same manner, by experiments upon the oil of bitter 
almonds, it is inferred that benzoic acid (C 14 H 5 .0 2 HO) has a 
base, which has been called benzoyl, symb. Bz., having tho 
formula C 14 H 5 2 , which also performs the part in composi- 
tion of an element, and constitutes the base of a large class 
of compounds. 

Ether also is supposed to have a base, (C 4 H 5 ) which is 
capable of combining with O.Cl.Br., giving rise to sulphuric, 



TJieory of Substitutions. 341 

chloric, and bromic ethers. All such bodies performing in 
composition the part of an element, are called compound radi- 
cals. Such radicals are supposed to exist in a large number of 
compounds, and have been made the basis of the classification 
of those bodies. They are, however, with a few exceptions, 
as cyanogen, mellone, and kakodyle, purely hypothetical bodies, 
that is, have never been isolated from their compounds. 
These hypothetical compounds are not supposed to exist in 
all organic bodies, and it is as yet impossible to make them 
the basis of a general classification. With regard to those 
bodies which are supposed to contain these compound radi- 
cals, some chemists, as M. Gerhardt, have explained their 
formation, and the changes which they pass through, on a 
theory which entirely dispenses with them. They can be 
of no use, unless it be to give us a clearer idea of the changes 
which take place in organic compounds; and if those 
changes are equally well explained on any theory which is 
capable of demonstration, it would seem to be' introducing 
numerous hypotheses which can be of no possible service, in- 
stead of a simple statement of facts. But, as it is desirable 
to present the subject of chemistry in its present state, we 
have concluded to describe those bodies which are supposed 
to contain such compound radicals, in one group, or as one 
class. Should M. Gerhardt's theory be received by chem- 
ists, it will not only render the doctrine of compound radicals 
unnecessary, but will probably require some changes in 
nomenclature, changes which he has made in his work. (See 
Gerhardt's Precis de Chimie Organique.) 

2. Theory of Substitutions. When oxygen, chlorine, bro- 
mine, and iodine, unite with various compounds, the latter 
give out hydrogen, and the process is termed dehydrogenize 
■ing. Thus, when dry chlorine gas is passed into pure oil of 
bitter almonds, (C u H0 2 +H,) it loses its atom of hydrogen, 
and an atom of chlorine is substituted, and the compound 
consists of C 14 H 5 2 +C1, a chloride of benzoyl. This and 



342 Organic Chemistry. 

other analogous facts have been generalized by Dumas, and 
the following general conclusions made : — 

(] .) That when a body is subjected to the dehydrogenizing 
action of 0, CI, Br, and I, it gains one of the latter for each 
atom it loses of hydrogen. 

(2.) But if the body contain water, it loses its hydrogen 
without any substitution. If, after this, hydrogen is ex- 
tracted, the substitution proceeds as before. 

(3.) The fundamental radical and its derivatives will be 
neutral or alkaline, whatever be the portion of oxygen, hy- 
drogen, &c, entering into it. But when the oxygen, bro- 
mine, &c, enter into combination with this radical they ren- 
der it acid. 

3. Pyracids. — Theory. When several of the vegetable 
acids are distilled, they undergo decomposition, and new 
acids are generated, which are called by the term pyracids. 
Tartaric acid becomes pyrotartaric acid ; gallic, pyrogallic ; 
and so of several others. The difference in composition 
seems to be that a quantity of water is expelled by the heat. 

Section I. Amylaceous and Saccharine Substances. 

Starch, C 12 H 10 O 10 . Starch exists abundantly in the vege- 
table kingdom. It. is a principal constituent of most kinds of 
grain, potatoes, and other farinaceous substances. It is ob- 
tained from potatoes by scraping them and washing in cold 
water, when the gluten, which is the other principal constitu- 
ent, remains in the hand, and the starch is mechanically dif- 
fused through the water. The water is then allowed to 
stand, and the starch subsides, while the saccharine and mu- 
cilaginous matters remain in solution. When made from 
the dough of wheat flour, and the water containing the soluble 
and insoluble parts of the flour is allowed to ferment, .acetic 
acid is formed, which dissolves the gluten and facilitates the 
separation of the starch. Starch exists in the vegetable or- 
gans in small granules, surrounded by sacks, which are 



Starch. — Diastase. 343 

broken by the process of grating or grinding, and the starch 
is thus separated. 

Properties. A white powder, soluble in hot water, forming 
a semitransparent jelly, but nearly insoluble in cold water. 
Its uses are well known. 

Starch is easily converted into sugar. In the germination 
of seeds, and in the malting of barley and other grains, this 
change takes place. If starch is boiled for a considerable 
time in water which contains one-twelfth of its weight of sul- 
phuric acid, it is converted into a kind of sugar, like that ob- 
tained from grapes. Arrow-root, prepared from the root of a 
plant, is a very pure starch. Sago, prepared from the pith 
of an East India palm tree, and tapioca and cassava, also 
from the root of a plant, are essentially the same. Inulin is 
a variety of starch found in the roots of the inula helenium, 
dahlia, and in certain lichens. It is a fine white tasteless pow- 
der, having the formula C 24 H ai 21 , (Parnell.) Lichen starch 
exists in several species of lichens. The cetraria Islandica 
{Iceland moss) yields a very pure variety of starch, which is 
used to form blanc mange. It forms a white opaque jelly. 
Starch forms compounds with chlorine, bromine, and iodine. 

Gelatinous starch, or amidin, is formed by rubbing the 
grains of starch with sand in a mortar. The coats of the 
starch granules are broken, and form a grayish white pow- 
der. By adding cold water, the mass expands into a trans- 
parent jelly. Mucilaginous starch, or dextrine, is formed by 
the action of acids, alkalies, diastase, and heat upon gelatinous 
starch. It is a white glutinous substance, resembling gum. 

Diastase is formed by the malting of grain. It is found in 
grain, the seeds of plants, and in the tubers of potatoes after 
germination. It is prepared by adding water to freshly 
malted barley and subjecting it to pressure. A viscid liquid 
is obtained, which, by heat and the action of alcohol, yields 
diastase. It is a white substance, remarkable for its property 
of converting starch into sugar. It is this substance which, 



344 Organic Chemistry. 

in the fermentation of grain, converts the starch into sugar 
and then the yeast which is added changes the sugar into 
alcohol and carbonic acid. 

Gluten. Gluten exists with starch in most kinds of grain. 
Jt is obtained from wheat flour by washing out the starch and 
soluble matter, and boiling the remainder in alcohol. On 
adding water and distilling off the spirit, gluten is deposited. 

Properties. Gluten is without taste, very tenacious, elas- 
tic, and insoluble in water. It ferments when kept warm and 
moist. The tenacity of common paste is owing to the gluten 
which it contains. 

The rising of bread is caused by the fermentation of glu- 
ten, the tenacity of which retains the bubbles of carbonic acid 
gas, which are generated in the process. Gluten consists 
mostly of vegetable albumen and jibrine, which may be ob- 
tained by the action of alcohol on the gluten of wheat and of 
other grains. 

Gum. Under this name are included all those vegetable 
principles which form, when dissolved in water, an adhesive 
viscid liquid, called mucilage] and which yield an acid, 
called mucic acid, when boiled with 4 times their weight of 
nitric acid. Gum is insoluble in ether and alcohol, and is 
precipitated by them from its aqueous solution, as an opaque 
white substance ; but in acids and alkalies, it is more soluble 
than in pure water. 

Gum Arabic is the most common variety of gum. It is 
obtained from several species of acacia or mimosa, in Africa 
and Arabia. It has the composition C 1S H 1] U . 

Gum Senegal differs in no important respect from gum Ara- 
bic. The gum of the peach, plum and cherry-tree, although 
identical in composition with gum arabic, differs in being in- 
soluble in cold water ; after being boiled, however, it assumes 
the characteristics of that gum. 

Gum Tragacanth differs from gum Arabic in containing a 
large portion of bassoric, starch, and water. It is tougher 



Ligni?i. — Xyloidine. 845 

than common gum. Gum tragacanth is therefore a very 
useful ingredient in paste. The jelly of fruits is distinct from 
gum in some properties, but is nearly allied in others. These 
substances have the composition C ia H"O u . 

Lignin. Lignin, or woody fibre, constitutes the fibrous 
structure of plants, and is the most abundant principle in 
them. The common kinds of wood contain about 90 per 
cent, of lignin. Lignin is insoluble in alcohol and water; 
with caustk) alkalies, and acids, it is much changed. With 
sulphuric acid it is changed into gum, and on boiling, is fur- 
ther changed into a sugar, like sugar of grapes. Straw, 
bark, and linen, may be converted in the same way into 
sugar. The lignin of lint, linen cloth, hemp, and straw, has 
the formula C 36 H 24 20 (Payen.) Lignin combines with the 
sulphate of copper, acetate of iron, chloride of mercury, and 
is preserved thereby from the dry rot. The wood of trees, 
as soon as they are cut down, will imbibe these salts in solu- 
tion, become impregnated with them, and rendered almost 
impenetrable to the ordinary agents of decay. 

Xyloidine, Gun-cotton (C 12 H 8 N 2 18 ) is formed by the action 
of nitric *acid on starch or woody fibre. To prepare gun- 
cotton, common cotton is carded to separate the fibres, and 
then immersed in a mixture of equal quantities of strong 
nitric and sulphuric acids for about 5 minutes. It is re- 
moved from the acid, washed in a large quantity of pure 
water, and then dried slowly under 212° F. It is then pre- 
pared for use. 

Properties. This substance, which has of late become so 
celebrated, does not differ in appearance from cotton, but 
possesses greater explosive qualities than gunpowder, ignites 
at a lower temperature, 360°, and is therefore more danger- 
ous to use, especially as it often explodes by sudden compres- 
sion, as when struck with a hammer. When ignited, it is 
wholly converted into gases and vapors. The products are 
Water or steam, carbonic acid and carbonic oxide gases. 
15* 



346 Organic Chemistry. 

It has been used with good results in blasting rocks, and 
for the same purposes as gunpowder. Owing to the compara- 
tive harmlessness of the products of its combination, its usa 
in deep mines would be preferable to that of gunpowder. 

Action of Oxygen on Woody Fibre, or Lignin. When any 
organic body is kept from the air, or from moisture, it will 
rarely decay. If wood is exposed to dry oxygen alone, it is 
acted upon but slightly, if at all, but when exposed to air 
and moisture, it suffers successive changes, which have been 
called by Liebig eremacausis, or decay. The oxygen of the 
air combines with the carbon of the wood to form carbonic 
acid, while the oxygen and hydrogen of the woody fibre unite 
and form water; but as two equivalents of water are formed 
for one of carbonic acid, the residue, after each change, con- 
tains a greater quantity of carbon than the wood itself, while 
its hydrogen and oxygen remain in the same relative propor- 
tions. The process is a slow combustion. The final result, 
however, is not carbon, but a pulverulent brown substance, 
described as humus, humic acid, geine, ulmine, ulmic acid. 
But when vegetable matter is suffered to decay under wa- 
ter, or away from the oxygen of the air, the products are 
carbonic acid, from the elements of the wood, carburet of 
hydrogen, tar and other matters rich in hydrogen. The final 
result in this instance is peat, lignite, and coal ; and it is in 
this way that we may account for the formation of the vast 
beds of coal which are laid up in the rocky strata of th8 
earth. This process is sometimes called putrefactive fer- 
mentation. When wood is subjected to destructive distilla- 
tion, a variety of compounds are formed, the more important 
of which are described in other parts of the work. 

Sugar. C 12 H n O n . Sugar is found in most ripe fruits, but 
more abundantly in the sap of the maple-tree, in the sugar- 
beet, and in the sugar-cane ; from the latter it is obtained by 
evaporating the juice at a moderate ebullition, until the syrup 
is sufficiently thick for the sugar to crystallize on cooling. 



Cans Sugar. — Grape Sugar, 347 

During this operation, lime-water is added to neutralize the 
acid present, and to remove impurities which rise with the 
lime in a scum to the surface ; it is next drawn off into shal- 
low coolers, in which it becomes a soft solid. Lastly, it is 
put into barrels with holes in the bottom, through which the 
molasses gradually runs out, leaving raw or brown sugar. 
Raw sugar is purified by boiling it with the white of eggs or 
bullock's blood and lime-water ; it is then received into coni- 
cal vessels, and in cooling assumes the form of loaf sugar. 

When two pieces of loaf sugar are rubbed together in the 
dark, phosphorescence is observed ; it is obtained in large 
crystals by fixing threads in a sirup, which evaporates grad- 
ually in a warm room : in this state it is called rock-candy. 
Sugar does not deliquesce when exposed to the air, except 
when impure, as raw sugar. It is soluble in an equal weight 
of cold water, and is much more soluble in warm water ; it 
is soluble in four times its weight of boiling alcohol, from 
winch solution fine crystals are obtained. The vegetable 
acids diminish the tendency of sugar to crystallize, as in 
molasses. 

By the action of sulphuric acid, starch and common wood 
may be converted into sugar. By the action of heat on cane- 
sugar, a brown substance is produced called caramel, C 12 H 9 
O' ; it is used for coloring spirits- Sugar combines with 
baryta, lime, oxide of lead., &c, forming unimportant com- 
pounds. 

Grape Sugar (C 12 H 14 14 ) exists in the juice of fruits, in 
honey, and In diabetic urine. It may be obtained from the 
i-uree of the sweet grape by adding chalk, clarifying with the 
white of an egg, evaporating, and setting aside to crystallize. 
But the process by which it is manufactured as an article of 
commerce, is to boil starch with from ~fo to ^g- of its weight of 
sulphuric acid, diluted with 4 parts of water, for 36 hours* 
adding chalk to separate the acid, and crystallizing. 

Properties, Grape sugar, as thus obtained, is white and 



348 Organic Chemistry. 

granular, rather less sweet than cane sugar, and less soluble 
in cold water, but more soluble in alcohol, from which it may 
be obtained in transparent cubic crystals. 

By the action of acids upon grape sugar, as the sulphuric, 
a new compound is formed, the sulpho-saccharic acid. The 
same acid decomposes cane sugar. But alkalies, such as lime 
and baryta, scarcely affect cane sugar, while they decompose 
grape sugar into formic, glucic, and melassic acids. 

Saccharic Acid (C 12 H 10 O 16 ) is formed by the action of 
dilute nitric acid on cane or grape sugar. It is soluble an«. 
sharply acid. It is remarkable for the variety of its com 
pounds, as the saccharate of potassa, ammonia, lead, zinc , 
and silver. The latter salt, when gently heated under wa- 
ter, is decomposed, and a metallic coat of silver is formed 
upon the sides of the vessel, resembling a mirror. 

Sugar of Milk, Lactine (C 34 H 24 24 ,or C 24 H 19 19 -f 5HO) 
exists only in the whey of milk, from which it may be obtained 
by evaporation, purifying the product with animal charcoal, 
and recrystallizing. It appears in the form of semi-transpa- 
rent quadrangular prisms, soluble in 6 parts of cold, and in 
2£ parts of hot water. This solution has a much sweeter 
taste than the crystals themselves. It is insoluble in alco- 
hol and ether. By the action of mineral acids it is converted 
into grape sugar. With the oxide of lead it forms two com. 
pounds, C 24 H 19 19 +5PbO, and C 24 H 19 O 19 +10PbO. 

Mucic Acid (C 12 H a 14 . 2HO) is formed by the action of 4 
parts strong nitric acid, 1 of water heated with 1 part of sugar 
of milk. A part of the lactine is converted into oxalic acid, 
and the mucic acid is deposited, on cooling, as a white crystal- 
line powder. Taste feebly acid, soluble in 6 parts of boiling 
water, and insoluble in alcohol. It is bibasic, combining with 
alkalies and metallic oxides, and forming two classes of salts. 
By the dry distillation of this acid, pyromuc?c acid is formed, 
C ,0 H 3 O 5 HO, 6 cquiv. of water and 2 equiv. of carbonic acid 



Fermentation. 349 

being separated, mucic ether (2C 4 H 5 0-fC 12 H ? 0) crystallizes 
in quadrangular colorless prisms. 

Honey consists of two kinds of sugar, one of which, when 
separated, crystallizes, and the other is uncrystallizable. Be- 
sides sugar, it contains gum, and probably an acid ; when- 
diluted with water, honey undergoes the vinous fermentation. 
Common sugar requires the addition of yeast for this change. 

Manna is the concrete juice of several species of ash, and 
owes its sweetness, not to sugar, but to a distinct principle 
called mannite, having the formula C 6 H 7 O a . 

Liquorice owes its sweetness to a saccharine principle 
which is quite distinct from sugar. 

Fermentation of Sugar, Starch, dc. 

Many vegetable substances, when exposed to warmth and 
moisture, undergo spontaneous changes, and the process is 
called fermentation. It is most commonly observed in sub- 
stances containing gluten, starch, gum, or sugar. In diffe- 
rent stages of the process, sugar, alcohol, and acetic acid 
are formed, and finally, there is a total dissolution of the sub- 
stance. These stages of the process are called the saccharine^ 
villous, acetous, and viscous fermentations. 

Saccharine Fermentation. Starch only is subject to this 
kind of fermentation. The quantity of sugar produced equals 
in weight half of the starch employed. The ripening of 
fruits has been regarded as a kind of saccharine fermenta- 
tion, in which the acid of the green fruit is converted into 
sugar ; this change is caused by heat, not by the vitality of 
the plant. 

Vinous Fermentation. When sugar with water, and yeast 
or some other ferment, is exposed to a warm temperature, 
ihe sugar is converted into carbonic acid gas and alcohol, in 
nearly equal weights of each. As starch is convertible into 
sugar by fermentation, if the process be continued under the 
nbove conditions, it will be converted into alcohol and car- 



850 Organic Chemistry. 

bonic acid. All vegetable bodies contain some substances 
which act as a ferment, and therefore, by the addition of 
moisture and regulation of the temperature, various kinds of 
grain containing starch, and of ripe fruit? containing sugar, 
will undergo the vinous fermentation. Thus cider is formed 
from apples, and beer from grain. To obtain ardent spirits, 
the fermented liquor is heated, and the alcohol passes over by 
distillation. 

In the fermentation of bread, the saccharine matter of the 
flour is resolved into alcohol and carbonic acid gas. The 
latter causes the dough to rise, and the former is entirely ex- 
pelled by the heat of baking. A company in London was 
formed for collecting the spirit emitted by the baking of 
bread. If the fermentation of dough be continued, it under- 
goes the change next described, and becomes sour. 

Acetous Fermentation. Any liquid which has undergone 
the vinous fermentation, or pure alcohol with water and 
yeast, exposed to the air in a warm place, undergoes a 
change, in which oxygen is taken from the air, and carbonic 
acid thrown off. In place of alcohol, acetic acid is found in 
the liquor. Thus cider becomes sour by age, if exposed to 
the air, and at length is converted into vinegar. In France, 
wine is converted into vinegar, and in England, an infusion 
of malt. 

Acetic acid is often formed in the spontaneous decomposi- 
tion of vegetable substances without sugar, in these cases, 
the process is quite different from the acetous fermentation, 
properly so called. 

Viscous Fermentation. This kind of transformation takes 
place in several bodies containing azotized albuminous sub- 
stances at certain stages of decomposition. Milk or cheesa 
curd mixed with sugar, when the temperature is raised from 
95° to 114°, undergo a change which renders the liquid viscid 
with the formation of mannite and lactic acid. A similar 
change takes place when the juices of beets and carrots are 



Compound Radicals. 351 

subjected to a high temperature and allowed to ferment ; also 
many animal substances, in the early stages of decay, give 
rise to similar products. 

Theory of Fermentation. The changes above described 
are explained by the fact, that when any body is in a state 
of decomposition, it has a tendency to induce changes in bodies 
with which it is in contact by the force of catalysis, see p. 300. 
This principle is extended by Liebig to matters of contagion, 
miasm, &c. Thus when any body in the atmosphere, or in 
contact with the living system, is in a state of decomposition, 
it induces a morbid action in the parts exposed, which, unless 
resisted by counteracting forces, extends its influence through- 
out the* body ; hence the danger of dissection in anatomical 
rooms ; a slight cut upon the hand with a knife used upon 
a subject which has passed to a certain state of putrefactive 
change, will often excite a morbid action through the whole 
body, and death is not unfrequently the result. 

Section II. Compound Radicals, or substances supposed to 
contain Compound Radicals. 

I. Alcohol, C*H 5 O.HO. Alcohol is always the product of 
fermentation. It does not exist readily formed in any living 
vegetable. It was discovered in the thirteenth century by 
the Arabians. 

Process. It is obtained from the fermentation of various 
grains and acidulous fruits by the process of distillation. As 
thus obtained, it is about one-half water, constituting various 
kinds of ardent spirits, from which pure alcohol is obtained 
by a second distillation, and the addition of dry carbonate of 
potassa to remove any remaining water. (See page 59.) 

Properties. Pure alcohol has a sp. gr. of .79, boils at 
173° F., is highly combustible, burning with a pale blue but 
hot flame. No smoke is produced in its combustion, and 
hence it is of great utility in the laboratory, using it instead 
of oil to heat various kinds of apparatus. Although exposed 
to a temperature of — 176°, pure alcohol has not been frozen. 



352 Organic Chemistry. 

Alcohol combines with water in every proportion. With an 
equal quantity of water, it constitutes spirit of the first proof ] 
sp. gr. about .92. The density will vary with the quantity 
of water. Its solvent properties are nearly equal to those of 
water, for which it has a strong affinity. 

Uses. As a solvent, alcohol is highly useful. Many vege- 
table principles not soluble in water are freely so in alcohol, as 
camphor, and many of the resins. Both mineral and vegeta. 
ble alkalies are soluble, but the other metallic oxides are 
insoluble. Proof spirit is also useful in cabinets of natural 
history, for the preservation of specimens of fishes, reptiles, 
or any other animals. Its uses in the arts are numerous and 
well known. 

Relation to Animals. Alcohol acts upon the animal system 
as a poison. When taken into the stomach, it has the prop- 
erty of passing into the circulation undigested. It irritates 
all the organs with which it comes in contact, and produces 
the most serious effects both upon the body and the mind. 
The stronger wines contain from 18 to 25 per cent., and the 
weaker from 12 to IT per cent, of alcohol. Beers, and all 
fermented liquors, contain more or less of alcohol. The in- 
toxicating effect .of wines is not so great as that of ardent 
spirits, which may be due to the chemical combination of al- 
cohol in them with mucilaginous and saccharine matters. 
And yet mostwines are more injurious to the system than 
ardent spirits, because of the acetate of lead and other poison- 
ous matters which are often added in their preparation. 

Alcohol is supposed to contain a radical called ethyle, hav- 
ing the formula OH 5 , and symbol E. On this theory it is 
called liydrated oxide of ethyle, EO+HO. The several com- 
pounds in which this radical is supposed to exist are called 
the ethyle series of com/pounds. 

Ether, Sulphuric Ether, Oxide of Ethyle, C 4 H 5 0. 

Process. Ether may be formed from alcohol by several 
processes. The easiest process, and the one always em. 



Ethers. 353 

ployed in the manufacture of this substance, is to boil in a 
glass flask about 5 parts of alcohol to 8 of sulphuric acid, al- 
cohol being gradually added, so as to preserve the liquid at 
the same level. The alcohol is decomposed into ether and 
water, which distil over through a tube, and are condensed 
in a receiver surrounded by ice-cold water. The ether floats 
on the top of the water, and is purified by a second distillation. 

Properties. Ether is a volatile transparent liquid sp. gr. 
.725, as commonly sold, .74, boils at 96°, at the common pres- 
sure ; invacuo at — 40° F., and evaporates rapidly at the ordin- 
ary temperature, producing a very intense cold. Its vapor 
is highly inflammable, and explosive when mixed with oxygen 
gas. When the vapor of ether is inhaled for a little time, it 
produces exhilarating effects, similar to the exhilarating gas. 
It possesses the property of rendering the system insensible 
to pain, hence it has been used much of late when surgical 
or dental operations are to be performed. 

Uses. Ether is sparingly soluble in water. It is used in 
medicine as a stimulant, and also applied externally to reduce 
the temperature in cases of inflammation. Ether combines 
with several acids, forming a series of salts. 

Hydrochloric Ether. Chloride of Ethyle (C 4 PPC1) is formed 
Dy the action of hydrochloric acid on alcohol. It is a color- 
less, highly volatile liquid, sp. gr. .874, boils at 52° F., neu- 
tral to test paper, and soluble in 24 parts of water. 

Hydrolromic Ether. Bromide of Ethyle (C 4 H 5 Br) is 
formed by mixing one part of bromine, four of alcohol, and 
one-eighth part of phosphorus, and distilling. A volatile 
transparent liquid comes over, rather denser than water. 

Hydriotlic Ether. Iodide of Ethyle (C 4 H 5 I) is obtained by 
distilling alcohol with hydriodic acid. It is a colorless liquid. 

Sulphuret of Ethyle (C 4 H 5 S) is formed by passing the va- 
por of hydrochloric ether through the proto-sulphuret of 
potassium. It is a colorless liquid, disagreeable odor, boiling 
at 163°.4 F. 

There is also a bisulphuret (C*H 5 S 2 .) 



354 Organic Chemistry. 

Tlieory. It will be perceived that all these compounds are formed by 
substituting an equiv. of CI. Br, &c. for O.HO in the alcohol, although 
there may be more complex changes in some of these processes than th« 
simple substitution of one substance for the other. 

Mercaptan (C 4 H b S-f HS) was discovered by Zeise, and 
may be formed by passing the vapor of hydrochloric ether 
through a strong solution of potassa saturated with sulphuret 
of hydrogen, and condensing the product in a cool receiver. 

Properties. It is a colorless liquid, with a penetrating 
garlic odor, boils at 100°. 

This substance acts with great power on several of the 
metallic oxides, and forms a singular class of compounds — ■ 
the mercaptides. 

Nitric Ether. Nitrate of Oxide of Ethyle, C 4 H 6 O.N0 5 . By 
the action of nitric acid on alcohol, nitrous acid and some 
other bodies are formed ; but if a small quantity of the ni- 
trate of urea is added, the nitric acid takes the place of the 
elements of one equiv. of water in the alcohol, and forms 
nitric ether, which distils over as a highly inflammable vapor, 
and condenses into a colorless liquid. Taste sweetish and 
agreeable, sp. gr. 1.112, boils at 185° F. 

Hyponitrous Ether. Hyponitrite of Oxide of Ethyle (C 4 
H 5 O.N0 3 ) is formed by the action of nitric acid on alcohol, 
but nitrous acid is also formed, which decomposes the ether. 
By pouring nitric acid on starch, hyponitrous acid is formed. 
If this acid is then passed through dilute alcohol, the acid 
takes the place of one equiv. of water, and hyponitrous ether 
distils over, and is condensed as a pale yellow liquid, having 
the fragrant odor of apples, sp. gr. .95, boils at 62° F. 

The sweet spirits of nitre used in medicine is prepared by 
distilling alcohol and nitric acid, and passing the vapor of the 
product through alcohol to absorb it. 

Carbonic Ether. Carbonate of the Oxide of Ethyle (C 4 H S 
O.CO 2 ) is prepared by dropping pieces of potassium into 
oxalic ether, until the evolution of gas ceases, and distilling 
a mixture of the brown paste thus formed with water, car 



Ethers. 355 

bonic ether distils over with the water, and is found floating 
on its surface in the receiver, as a colorless liquid ; odor aro- 
matic, taste burning, boils at 259° F. 

Boracic Ether (C 4 H 6 O.B0 3 ) is obtained by the action of 
chloride of boron on alcohol, as a limpid liquid. Taste burn- 
ing, boils at 246°. sp. gr. .885. By the same process, a vitri- 
ous solid compound is formed, having the formula C 4 H & . 
2BO\ 

Silicic Ethers. Silicate of the Oxide of Ethyle. Two ethers 
are formed by the action of the chloride of silicon upon alco- 
hol, similar in constitution to the preceding compounds. Both 
are volatile liquids, odorous, with a hot burning taste. 

Oxalic Ether. Oxalate of the Oxide of Ethyle (C 4 H 5 O.C a 
O 3 ) may be obtained by distilling a mixture of 4 parts of bin- 
oxalate of potassa, 5 parts of sulphuric acid, and 4 parts of 
strong alcohol, nearly to dryness, and collecting the products 
in a receiver, kept warm to dissipate any common ether formed 
in the process. The impure ether is separated by water and 
re-distilled. It is an oily liquid, colorless, having a very 
pleasant aromatic odor, sp. gr. 1.09, boils at 363° F. De- 
composed by caustic, alkalies, and converted, by a solution of 
ammonia, into oxamide and alcohol. 

Acetic Ether (C 4 H 5 O.C 4 H 3 3 ) is prepared by heating a 
mixture of 3 parts of acetate of potassa, 3 of alcohol, and 2 
of sulphuric acid. The distilled product is purified by a lit. 
tie chalk, then with fused chloride of calcium, water being 
added to separate the alcohol. It is a liquid, limpid, and of a 
very fragrant odor, sp. gr. .89, boils at 165° F. It is decom- 
posed by alkalies. 

Formic Ether (C 4 H 5 O.C 2 H0 8 ) is formed by distilling 7 
parts of dry formate of soda, 10 of sulphuric acid, and 6 of 
alcohol. The ether is separated from the products by mag- 
nesia and chloride of calcium. It requires several days to 
complete the process. It is a colorless liquid, with an aro- 
matic odor, sp. gr. .915, boils at 133°. 



356 Organic Chemistry. 

(Enanihic Ether (C 4 H 5 O.C 14 H 13 2 ) is obtained in the pro< 
cess of distilling certain wines, as an oily thin liquid of a pe- 
culiarly powerful odor of wine. It appears to be formed by 
the action of an acid called oenanthic, which is generated in 
the process of fermentation. It is this ether which gives the 
peculiar aroma to wines. 

Benzoic Ether (C 4 H 5 0+C 14 H 5 3 ) is an oily liquid, obtained 
by the distillation of a mixture of 4 parts of alcohol, 2 of ben- 
zoic, and 1 of hydrochloric acids. 

Tluory. In the above compounds one equivalent of the acid is substi' 
tuted for the elements of an equivalent of water (HO) in the alcohol. 

Sulphovinic Acid (C 4 H 5 0. 2S0 3 +HO) is prepared by 
mixing equal weights of sulphuric acid and alcohol, heating 
the mixture to the boiling point, and after being allowed to 
cool, adding a quantity of water, and sufficient chalk to ren- 
der it neutral. The whole is then filtered, and the solution 
evaporated by the heat of a water bath, filtered again, and 
crystallized. By this process we obtain sulphovinate of 
lime in colorless transparent crystals. Efflorescent in dry- 
air, and soluble in water. By substituting carb. of baryta 
for chalk, a similar salt of baryta is formed, and from this 
sulphovinic acid may be obtained by adding dilute sulphuric 
acid, to precipitate the baryta, and evaporating in vacuo. It 
is a syrup-like liquid, sour to the taste, and easily decom- 
posed. When the temperature is raised above 320° it yields 
water and olefient gas. 

Phosphovinic Acid (C 4 H 5 0. P0 5 +2HO) is obtained in a 
similar manner with the above, using phosphoric acid instead 
of sulphuric. It resembles the preceding substance in its 
properties, uniting with bases, and forming a class of salts. 

Heavy Oil of Wine. This substance is obtained as a yel- 
lowish oily liquid, when 2£ parts of sulphuric acid and 1 
oart of alcohol are distilled. After being purified, it is 
heavier than water, nearly insoluble in that liquid, solu- 
ble in alcohol and ether. In contact with boiling water, it is 



Products of the Oxidation of Alcohol, &c. 35? 

converted into sulphovinic acid, and an oily liquid, — the 

sweet oil of wine. When this latter substance is left to cool, 

it deposits white tasteless crystals of a substance called ether- 

ine, and there remains a yellowish oily liquid, lighter than 

water, called etherole. These substances are isomeric with 

olefiat gas, C 4 H 4 . 

Theory. The above acid compounds are formed in the usual manner 
by substitution, but differ from the preceding in possessing acid properties. 

II. Products of the Oxidation of Alcohol and Ether. 

When alcohol and el her are acted upon by nitric acid and 
other oxidizing agents, a series of compounds are formed, 
which have been supposed to contain a new radical — Acetyle, 
C 4 H 3 =Ac. 

Aldehyde (C 4 H 3 O.HO) is prepared by several processes, 
by passing the vapor of ether, or of alcohol, through a red hot 
tube, and by distilling sulphuric acid 6 parts, 4 of alcohol, 4 
of water, and 6 of oxide of manganese. 

Properties. It is a colorless liquid, with a suffocating 
ethereal odor, sp. gr. .79, boils at 7 2°F., soluble and neutral, 
but becomes acid on exposure to the air, and unites with bases 
to form salts. When kept for a long time, two new isomeric 
bodies are formed, eladehyde and metaldehyde. Aldehyde is 
similar in constitution to alcohol. 

Aldehydic Acid. Acetous Acid (C 4 H 3 2 .HO) is obtained 

by passing sulphuret of hydrogen through a solution of alde- 

hydate of silver. It is also formed by the slow combustion 

of ether. 

Exp. Put a few drops of aldehyde into a little water in a test tube, then 
add nitrate of silver and ammonia to precipitate the oxide of silver. If 
now the tube be heated by a spirit lamp, the silver will be deposited on 
the surface, giving it the appearance of a mirror. 

Acetic Acid. Vinegar. C 4 H 3 3 .HO. This acid exists 
in 'the sap of many plants, and is generated in large .quantities 
by the acetous fermentation. It is the acid of common vine- 
gar. To obtain acetic acid in a pure state, saturate distilled 
vinegar with a metallic oxide, as of copper or lead, and distil 



358 Organic Chemistry. 

the compound. Distilled vinegar is mostly acetic acid. If 
may also be obtained in a concentrated state by distilling dry 
acetate of soda with sulphuric acid, and subjecting the prod- 
ucts to cold, the pure acid crystallizes out in the solid state. 
Pyroligneous Acid consists of acetic acid mixed with tar and 
a volatile oil, and is obtained by the dry distillation of wood. 
Alcoholic spirits, by the aid of ferment, are converted into 
acetic acid. 

Properties. Acetic acid is solid below 60° F., but contains 
one equiv. of water, which appears to be essential to its 
constitution. The liquid acid is transparent, has a fragrant 
and refreshing odor, and sharp acid taste, sp. gr. 1.065, boils 
at 248°, soluble in water, alcohol and ether, and highly cor- 
rosive to the animal organs. It forms a numerous class of 
salts, all soluble in water. 

Uses. The uses of vinegar are well known. The pure 
acid is much used in analytical processes, and the crude acid 
for forming several compounds used in the arts, as white 
lead. 

Acetate of Potassa (C 4 H 3 3 .KO) is formed by decomposing 
the carbonate of potassa with acetic acid. It is a white de- 
liquescent salt, much used in medicine. 

Acetate of Ammonia. Spirit of Minder eus is a medical 
preparation, formed by the direct union of ammonia with the 
acid when they are brought in contact. It is a very soluble 
and volatile solid. 

Neutral Acetate of Lead — Sugar of Lead. C l H 3 3 .3HO 
PbO. This substance, commonly known under the name 
of sugar of lead, may be prepared by dissolving the carbonate 
of lead, (white lead) or litharge, in distilled vinegar. It is 
obtained as a white crystalline salt, of a sweetish astringent 
taste, and is highly poisonous. It is used in medicine, and 
by dyers and calico printers for the preparation of acetate of 
alumina and of iron. ■ 

Tri-acetate of Lead (C 4 H 3 3 . 3PbO) is prepared by mixing 



Acetates of Lead and Copper. 359 

7 parts of litharge with a solution of 6 parts of sugar of lead. 
The salt crystallizes from the solution in long slender needles, 
very soluble in water, with an alkaline reaction. It is used 
in medicine under the name of Goulard's extract of lead. 
This salt contains 3 equiv. of the oxide of lead, two of which, 
on exposing the salt to the air or carbonic acid, combine with 
2 equiv. of the acid, and form the well known paint white 
lead, while the other equiv. of oxide remains in combination, 
forming the neutral acetate. 

In the manufacture of white lead, the tri-acetate performs 
an essential part. Plates of lead are exposed to the influence 
of acetic acid, water, air, and carbonic acid. The oxygen of 
the air forms a film of oxide on the plates, which combines 
with the acetic acid, forming the neutral acetate ; this latter 
substance acts on the oxide of l^ad, and forms the tri-acetate. 
This is decomposed by the carbonic acid into white lead, and 
the neutral acetate, which again unites with more oxide, 
formed by the oxygen of the air, reproducing the tri-ace- 
tate, which is again decomposed by the carbonic acid. The 
process once begun by a small quantity of acetic acid, will 
continue to produce white lead from the pure lead, until the 
metal is all exhausted. 

Acetates of Copper. Of these three or four are known. 
The neutral acetate (C 4 H 3 3 .CuO + HO) is formed by dis- 
solving verdigris in hot acetic acid, and crystallizing from 
the filtered solution. It forms beautiful crystals of a dark 
green color, soluble in water and alcohol. Verdigris is a 
variable mixture of the several acetates of copper, and is pre- 
pared in France by covering copper plates with the refuse 
of grapes after the wine has been extracted. A better arti- 
cle is prepared in England by covering copper plates with 
cloths soaked in pyroligneous acid. 

Acetate of Alumina (?C 4 H 3 3 +AP0 3 ) is much employed 
by calico printers as a mordant for fixing colors. It is pre- 
pared for this purpose by mixing acetate of lead and alum 



860 Organic Chemistry. 

(sulphate of alumina and potassa) in solution, and filtering 
Gum is put into the filtered liquid to thicken it, and then i\ 
is applied to the cloth by a stamp. A moderate degree of 
heat drives off the acetic acid and the alumina unites with the 
dye. Acetate of iron is also used for the same purpose. 
Acetate of zinc is sometimes applied externally as a remedy. 
Several other acetates are known, most of which are of little 
importance. 

Acetone, Pyracetic Spirit (C 3 H 3 0) is obtained by decompos- 
ing acetic acid, or metallic acetates, by heat. It is a color- 
less volatile liquid, very inflammable, burning with a bright 
flame, sp. gr. .792, boils at 132° F. When this substance is 
distilled with half its volume of Nordhausen sulphuric acid, 
another inflammable liquid is obtained, (C 3 H 2 ) and by the 
action of perchloride of phosphorus on acetone, an oily liquid 
separates, (C 6 H 5 C1.) 
* 

III. Kakodyle and its Compounds. 
, Kakodyle, C 4 H 6 As=Kd. This substance is considered as 
one of the compound radicals, one of the few which have 
been proved to have an existence. It was discovered by 
M. Bunsen. It is a colorless liquid, crystallizing on ex- 
posure to cold, odor offensive, resembling arseniuret of hydro- 
gen, takes fire in the air and in chlorine gas. It is very 
poisonous. Kakodyle forms a large class of compounds, in 
which it performs the part of a simple metal. 

Protoxide of Kakodyle — Alkarsine, C 4 H 6 AsO. This sub- 
stance has been long known as Cadefs fuming liquid. Pre- 
pared by heating equal weights of dry acetate of potassa and 
arsenious acid to redness in a glass retort, and condensing the 
products in a receiver surrounded with ice. 

Properties. A colorless ethereal liquid, very offensive odor, 
sp. gr. 1.462, boils at 300° F. ; subjected to cold, 9° F., il 
crystallizes in silky scales. Takes fire in the air, after 
emitting a dense white smoke, and explodes in contact with 






Kakodyle and its Compounds. 361 

nitric acid. Its vapor attacks the eyes and mucous surfaces 
of the nose, even in small quantities. Inhaled, it is highly 
poisonous and destructive of life. 

Kakodylic Acid. Alkargene (C 4 H 8 As0 3 , or KdO 3 ) is formed 
by slowly oxydizing kakodyle, or its oxide, by means of add- 
ing oxide of mercury to kakodyle covered with water. The 
acid crystallizes from this solution in oblique rhombic prisms, 
permanent in dry air, deliquescent when exposed to moisture ; 
very soluble in water and alcohol ; combines with oxides and 
forms salts. It is distinguished from the other compounds of 
kakodyle by not being poisonous. 

Chloride of Kakodyle (C 4 H 8 AsCl=KdCl) is formed by 
distilling hydrochloric acid with an alcoholic solution of oxide 
of kakodyle previously mixed with a dilute solution of corro- 
sive sublimate. It is a colorless liquid of a very offensive 
odor, and highly poisonous. 

Iodide of Kakodyle (Kdl) is prepared by distilling hydrio- 
dic acid with oxide of kakodyle. It is a yellowish liquid — 
very offensive odor. Kakodyle also unites with bromine and 
fluorine, forming similar compounds, 

Sulphuret of Kakodyle (KdS) is a thin colorless liquid, fe- 
tid odor, and spontaneously combustible in air or oxygen gas. 
It dissolves sulphur, and produces a persulphuret of kakodyle, 
(KdS 3 ) which is one of the sulphur acids capable of uniting 
with sulphurets of gold, copper, bismuth, lead, and antimony 
and thus of forming an interesting class of double salts. 

Cyanide of Kakodyle (KdNC 2 ) is prepared by distilling the 
oxide of kakodyle with strong hydrocyanic acid. It is liquid 
above 91° F., below that point it crystallizes in four-sided 
prisms of a beautiful diamond lustre. Its vapor is poisonous 
in the highest degree ; a few grains will so affect the atmos- 
phere of the room as to produce numbness in the hands 
and feet, vertigo, unconsciousness, and even death, if long 
iespired. 

16 



862 Organic Chemistry. 

IV. Products of the Dry Distillation of Wood. 

When wood is subjected to destructive distillation, at a red 
heat, several substances are formed, the most important of 
which are tar and pyroxylic, or wood spirit, which is an alco- 
hol of a series of compounds, containing, as it is supposed, a 
new radical methyle, C 2 H 3 =Me. 

Methylic Ether. Oxide of Methyle (C 2 H 3 0=MeO) is pre- 
pared by distilling a mixture of 1 part of wood spirit with 4 
of sulphuric acid, and transmitting the gas through milk of 
lime, and then through pure water, which dissolves the ether. 
From this liquid the gas is obtained by boiling it, and col- 
lecting over mercury. 

Properties. A colorless gas, of an ethereal odor, combusti- 
ble, soluble in water and sulphuric acid. It acts as a base, 
and unites with the strongest acids to form a class of salts. 

Pyroxylic Spirit, Wood Spirit, Hydrate of Oxide of Me- 
thyle. C 2 H 3 0-f-HO=MeO+HO. 

Process. When the impure acetic acid obtained by the 
distillation of wood is saturated with quick-lime and distilled, 
impure wood spirit first comes over, which is purified by re- 
peated distillation with chloride of calcium and water. It 
exists also in oil of winter-green. 

Properties. A volatile colorless liquid, disagreeable odor, 
pungent taste, burns with a pale blue flame, soluble in wa- 
ter, alcohol, and ether, sp. gr. .798, boils at 151.7° F. It 
dissolves, by the aid of heat, sulphur and phosphorus in small 
quantities. Its solvent properties resemble alcohol. 

Uses. It is used in the arts to dissolve resins, in the man- 
ufacture of spirit varnishes. In medicine, it has been used 
for affections of the. lungs, under the name of wood naptha ; 
but its medicinal virtues are not generally acknowledged. 

Chloride of Methyle (C 2 H 3 Cl=MeCl) is obtained by the 
action of 2 parts of common salt, 3 of sulphuric acid, and 1 
of wood spirit. The chlorine of the salt displaces the oxygen 
and water in the wood spirit, and gives rise to a colorless gas 
of an ethereal odor and sweet taste, sp. gr. 1.731. 



Meihyle Series of Compounds. 363 

Iodide of Meihyle (C 2 H 3 I=MeI) has been obtained as a 
colorless liquid, slightly inflammable, sp. gr. 2.24 

Fluoride of Meihyle (MeF) is obtained as a colorless gas, 
and 

Cyanide of Meihyle (MeCy) as an ethereal liquid. 

Sulphuret of Meihyle (MeS) is a limpid liquid of very offen- 
sive odor. 

Theory. It will be seen that the above compounds are formed by dis- 
placing 0-}-HO from wood spirit by CI. I. F.S., &c., or perhaps hydrogen 
from one of the bodies unites with the oxygen of the oxide of methyle to 
form water, and these simple bodies unite directly with the methyle, dis- 
placing only HO from the wood spirit. 

Sulphate of Oxide of Methyle (C 2 H 3 0+S0 3 =MeOS0 3 ) is 
easily prepared by distilling 1 part of wood spirit with 8 or 
10 of sulphuric acid. A colorless oily liquid distils over into 
the receiver, which is purified by caustic baryta. It has an 
alliaceous odor, sp. gr. 1.324, boils at 370° F., insoluble in 
water, decomposed by boiling water into sulpho-methylic acid 
and wood spirit. 

Nitrate of Oxide of Methyle (MeO.+NO 6 ) is formed by 
pouring 1 part of wood spirit, and 2 of sulphuric acid, on 
1 part of nitrate of potash, in a glass retort, and collecting 
the products in a receiver. This is purified by repeated dis- 
tillations with water and chloride of calcium. The pure ni- 
trate is an ethereal colorless liquid, sp. gr. 1.182, boils at 150°, 
and burns with a yellow flame. Its vapor is very dense, and 
when heated above 300° explodes with great violence ; de- 
composed by causiic potash into nitre and wood spirit. 

Oxalate of Oxide of Methyle (MeO.C-O 3 ) is obtained in 
the form of a spirituous liquid, by distilling equal weights of 
oxalic acid, wood spirit, and sulphuric acid, and condensing 
the products in a receiver. This, when exposed to the 
air, yields rhombic crystalline plates, colorless, with the 
odor of oxalic ether; melts at 124°, and boils at 322°, solu- 
ble in o lcohol and water. The latter substance decomposes 
it into oxalic acid and wood spirit. 



364 Organic Chemistry. 

Acetate of Oxide of Methyle (MeO.C 4 H 3 3 ) is prepared ty 
distilling 1 part of acetic acid, 1 of sulphuric acid, and 2 of 
wood spirit. It resembles acetic ether, and is isomeric with 
formic ether. 

Suipho-methylic Acid, Me0.2S0 3 +HO. This acid is ob- 
tained by adding sulphuric acid to sulpho-methyliate of baryta, 
It is a sour sirupy liquid, which may be made to deposit aci- 
cular crystals. Soluble in water and alcohol, easily decom- 
posed by heat. It unites with metallic bases to form salts. 

^ Theory. In the preceding compounds, the acids unite with the oxide 
of methyle, displacing HO from wood spirit. 

V. Formic Acid (C a H0 3 -f HO) is a secretion from the red 
ant, from which it derives its name. It may be formed by 
the action of platinum black on wood spirit, and by trans 
mitting dry sulphuret of hydrogen through a solution of for- 
mate of lead. 

Properties. It is a colorless liquid, powerfully acid, odor 
exceedingly penetrating, sp. gr. 1.235, boils at 212°, and 
crystallizes in large brilliant plates when cooled below 32° F. 
Its vapor burns with a bluish flame. The pure acid blisters 
the skin. Decomposed by sulphuric acid, with the escape 
of carbonic oxide, unites with oxides, and forms a class of salts 
which resemble those of acetic acid, but which are distin- 
guished from acetates by precipitating the oxide of silver or 
mercury from their combinations. 

Formic acid is supposed to have a radical (C 2 H, symb. Fo.) 
called Formyle, with which O. CI. Br. I., &c, unite to form a 
series of compounds. This base is derived from methyle by 
removing 2 equiv. of hydrogen. 

Formates. Formic acid unites with soda, formin g formate 
of soda, a crystalline solid, very soluble, and easily decom- 
posed by sulphuric acid, with escape of carbonic acid. 

Formate of Potassa is not easily crystallized. 

Formate of Ammonia is easily decomposed by heat into hy 
drocyaniG acid and water. There are also formates of baryta^ 



Potato Oil. 365 

ttronta, lime, magnesia, lead, cobalt, and several other metal. 
lie oxides. Formate of copper crystallizes in beautiful, blue, 
rhombic prisms. Formates of mercury and silver are easily 
decomposed by a gentle heat, the metal being precipitated 
frith escape of carbonic acid. 

CMoroform Perchloride of Formyle (C 2 HC1 3 ) is best ob- 
tained by distilling a mixture of 1 part of alcohol or wood 
spirit, 3 of chloride of lime, and 24 of water, in a large vessel. 
A heavy oil collects in the receiver, which, when rectified, 
is a thin colorless liquid, of an agreeable ethereal odor and 
sweetish taste, sp.gr. 1.48, boils at 141° F. Dissolved in 
alcohol, it is used in medicine under the name of chloric ether. 
By the action of chlorine, we obtain C 2 C1 4 , oi bichloride of 
carbon. Its vapor when respired renders the system insensible. 

Bromoform. Perbromide of Formyle (C 2 HBr) is prepared 
in the same manner with the preceding, using bromine in- 
stead of chlorine. It is a heavy volatile liquid. 

Iodoform (C 2 HP) is also formed in the same manner. It is 
a yellow crystalline solid. Both of these compounds are de- 
composed by a solution of potash in alcohol. 

VI. Potato Oil—Amylic Alcohol, C 10 H n O.HO. This 
substance distils over with the potato brandy in the manu- 
facture of the latter article, as an acrid volatile oil. In its 
constitution it is similar to alcohol, and has been supposed to 
be a hydrated oxide of a new radical, amyle, C 10 H n . symb, 
Ayl. This hypothetical radical unites with O.Cl.Br, I and S, 
forming a series of compounds similar to acetyle, &c. 

Chloride of Amyle (C 10 H".C1) is prepared by distilling 
equiv. weights of potato oil and perchloride of phosphorus. 
It is a liquid of an agreeable aromatic odor, insoluble and 
neutral ; burns with a flame tinged with green, boils at 215°. 
By the action of chlorine exposed to sunshine, another com- 
pound is formed, chloruret of chloride of amyle, (C ]0 H 3 C1 9 ) the 
chlorine replacing a portion of the hydrogen; 



366 Organic Chemistry. 

Bromide of Amyle (C 10 H 1] Br) and the Iodide of Amyh 
(C 10 H n I) are volatile liquids, somewhat similar in theil 
properties. 

Sulphamylic Acid (C 10 H n O+SO 3 HO) may be obtained by 
precipitating it from its combination with oxide of barium, by 
means of dilute sulphuric acid. It has an acrid bittef taste, 
and forms salts with metallic oxides. 

VII. Valerianic Acid (C 10 H 3 O\HO) exists in the root of 
the Valeriana officinalis, from which it may be obtained by 
distillation. It is also prepared by heating potato oil with 
quicklime and hydrate of potassa. The valerianate of potassa 
thus formed is distilled with dilute sulphuric acid. 

Properties. A colorless oil, sharp acid taste, odor of vale 
rian root, burns with a bright smoky light, sp. gr. .937, boils 
at 374°. 

Uses. Used in medicine, in the form of valerianate of 
zinc. The medicinal qualities of the valerian root are due 
to the presence of this acid. 

Valerianic acid is supposed to contain a base radical called 
valeryle, (C 10 H 9 , symb. VI) which forms a series of com- 
pounds analogous to the other hypothetical radicals. 
• 
VIII. Oil of Bitter Almonds and its Products. 

This oil is supposed to contain a compound radical called 
Benzoyle, C u H 5 2 Bz, which unites with O.Cl.Br.I.S, &c, 
and forms a series of compounds. 

Bitter Almond Oil is considered a Hydruret of Benzoyle, 
C 14 H 5 2 +H=BzN. This compound is obtained by digest- 
ing in water, for some hours, crushed bitter almonds, and dis- 
tilling. An oily liquid passes over, containing the pure oil, 
mixed with hydrocyanic acid and some other substances, 
This is purified by adding protochloride of iron, hydrate of 
lime, and distilling again. 

Properties. A colorless liquid, odor very fragrant, tasta 



Benzoic Acid. — Chloride of Benzoyle. 367 

pungent, sp.gr. 1.073, boils at 350° F. The vapor burns 
with a bright smoky flame. The crude oil is poisonous, but 
when perfectly pure it is not injurious. 

Uses. Extensively used by perfumers, for giving an agree- 
able flavor to puddings, custards, &c. Exposed to the air, 
2 equiv. of oxygen combine with it, and form 

Benzoic Acid, C 14 H 5 3 .HO, which also exists in a fra- 
grant resin, obtained from a species of the laurus (laurus 
benzoin) in the balsam of Peru, and in several other vegeta- 
ble substances. 

Properties. Benzoic acid crystallizes in soft white scales, 
flexible, transparent, and of a pearly lustre, or in hexagonal 
needles ; is slightly biting, but of a sweetish taste, producing 
sensation in the throat. When warmed, it is slightly fra- 
grant. Fuses at 248°, and sublimes a little above, and boils 
at 462° F. 

Exp. Suspend a small branch of a shrub in a tall glass without a bot- 
tom ; place a small quantity of the acid upon a plate of metal ; place the 
jar over the plate, at the same time applying the heat of a lamp to evapo- 
rate the acid, and the branch will soon be covered with delicate white 
crystals. 

Benzoic acid combines with metallic bases, and forms a 
large but unimportant class of compounds, the Benzoates — 
1 equiv. of acid to 1 of base. 

Chloride of Benzoyle (C 14 H & 2 .Cl=BzCl) is prepared by 

passing chlorine gas through bitter almond oil, and heating 

tne yellow liquid thus formed to expell excess of chlorine. 

Tlicory. One equiv. of chlorine takes the place of one equiv. of hy- 
drogen, by simple substitution. 

Properties. A colorless liquid, odor penetrating and dis- 
agreeable, sp. gr. 1.106, boils at 383°. Its vapor burns with 
a greenish tint. Slowly decomposed by cold water into ben- 
zoic and hydrochloric acids ; by alcohol into HC1 and benzo- 
ate of ether. With alkalies it yields a benzoate and a chlo- 
ride. By distilling this substance with metallic bromides, 
iodides, sulphur ets, &c, compounds are formed similar to the 



368 Organic Chemistry. 

chlorides. By passing dry ammoniacal gas through chlonds 
of benzoyle, a white solid is formed, called 
Benzamide, C 13 H & 3 .NH 2 =BzNH 2 . 

Theory. CI unites with one equiv. of H of the NH 3 , leaving NH 2 in 
combination. 

This substance is purified by solution in water, from 
which pure benzamide crystallizes in right rhomboidal prisms 
or plates, of a pearly lustre. Fuses at 239° ; decomposed 
by acids and alkalies, if water be present, into ammonia and 
benzoic acid. 

Benzole (C 12 H 6 ) was discovered by Faraday, and called bi- 
carburet of hydrogen. It may be obtained by heating 1 part 
of benzoic acid with 3 of slacked lime. It is a limpid liquid, 
with an agreeable ethereal odor; sp.gr. .85, boils at 187° F. 
insoluble in water, but soluble in alcohol and ether. When 
decomposed by acids, it forms several compounds, as sulpho- 
benzole, C 12 H & S0 2 , nitro-benzole, C 12 H 5 N0 4 . An equivalent 
of hydrogen unites with one equiv. of oxygen in the above 
acids to form water, and SO 2 and NO 4 remain in combination 
with the benzole. Br. and CI. and I. and N. unite with ben- 
zole, and form unimportant compounds. 

Benzoine (C 14 H 6 3 ) is obtained by mixing equal quantities 
of bitter almond oil and an alcoholic solution of potassa. By 
repeated crystallization, it is obtained in colorless prisms > 
without odor or taste. It is isomeric with the oil of bitter 
almonds. 

Benzile (C 14 H 5 2 ) is obtained by passing chlorine gas 
through benzoine in a state of fusion. It is a yellowish 
crystalline solid, inodorous and tasteless. This substance 
has the composition assigned to the hypothetical radical ben* 
zoyle, and has been supposed to be an isomeric modification 
of it. It would seem preferable to make it the radical of the 
series ; but the series of compounds it forms, by the action 
of other bodies, does not seem to favor such a view. The ben- 
zoyle series of compounds are very numerous — only the most 



Amydaline. Saliccne. 36 ( J 

important have been described. The two following sub- 
stances are also obtained from bitter almonds, and are virtu- 
ally related to this series. 

Amygdaline (C 40 NH 27 O 22 ) exists also in the seed of the 
peach and cherry-laurel. It is obtained by the action of boil- 
ing alcohol upon the almond cake, or substance which remains 
when bitter almonds are pressed to obtain the oil. It crystal- 
lizes in large transparent prisms, having a silky lustre. By 
the action of alkalies it yields 

Amygdalic Acid, (C 40 H a6 O 24 .HO) which has a very agree- 
able acid taste, capable of forming a class of salts, the amyg- 
dalaies, of which little is known. 

Synaptase, or Emulcine, is another singular body, consti- 
tuting the white portion of both sweet and bitter almonds. It 
is very soluble in water, of uncertain composition. 

Hippuric Acid (C 18 NH 8 5 .HO) is formed from benzoic acid 
In a very singular manner. When benzoic acid is taken into 
the stomach, the urine formed will contain hippuric acid in 
quantities greater than that of the benzoic acid swallowed. 
It also exists in the urine of the horse and cow. When pure, 
it is in the form of beautiful white crystals, of a slightly bit- 
ter taste. By a high temperature it is converted into benzoic 
acid and benzoate of ammonia. When the urine of the horse 
is left to putrefy, its hippuric acid is converted wholly into 
benzoic acid. 

IX. Salicene (C 4, H 29 22 ) is a peculiar bitter principle 
which exists in the leaves and bark of the willow, poplar, 
and some other trees. It may be prepared by heating the 
bark with boiling water, and digesting the evaporated liquid 
with oxide of lead, and then precipitating the lead bysulphu- 
ret of hydrogen. On evaporation, salicene crystallizes, and 
s purified by animal charcoal. 

Properties. Salicene appears in the form of small silky 
needles, having an intensely bitter taste. On heating, it is 
16* 



370 Organic Chemistry. 

decomposed, and burns with a bright flame. Soluble in wa« 
ter and alcohol. 

Uses. Used extensively in medicine as a tonic. By dis- 
tilling salicene with sulphuric acid and bichromate of potassa, 
a yellow sweet-scented oil is produced, which is found to be 
identical with the volatile oil from the flowers of the common 
meadow-sweet, (spirea ulmaria) and is called 

Hydrosalicylic Acid, and Salicid of Hydrogen, C 14 H 5 4 .H. 
This substance is supposed to contain a new compound, radi- 
cal, Salicyle, (C 14 H 5 4 — Sa) which forms a series of com- 
pounds analogous to henzoyle. Hydrosalicylic acid is an oily 
liquid, fragrant odor, and burning taste; sp. gr. 1.173, boils 
at 380°, soluble in water, reddens litimus, and gives a vio- 
let color to the pure salts of iron ; soluble in alcohol and 
ether. 

Salicylic Acid (C 14 H 5 4 .0) is prepared by heating hydru- 
ret of salicyle with solid hydrate of potassa in excess, dis- 
solving the fused mass in water and adding a little hydrochlo- 
ric acid. The acid crystallizes from the solution in small 
white crystals, sparingly soluble in water, and very soluble 
in alcohol and ether. It exists in oil of winter-green, and 
may be obtained from it by heating it with a solution of 
potassa, and adding hydrochloric acid to separate the potassa. 
It somewhat resembles benzoic acid. 

Chloride of Salicyle (C 44 H 5 4 ) is obtained by action of 
chlorine gas on salicylic acid, the CI taking the place of the 
oxygen. It crystallizes in tabular crystals of a pearly 
lustre ; odor disagreeable, taste hot and pungent. It com- 
bines with metallic oxides, such as potassa, baryta, &c. 
Bromine and iodine also displace one equiv. of oxygen from 
salicylic acid, and form compounds analogous to the corres- 
ponding compounds of benzoyle. 

Phloridzine (C 42 H 2S 18 . 6HO)"exists in the bark of the roof 
of the apple, pear, plum, and cherry-tree, and may be ob- 
tained from the bark by the action of boiling alcohol. It re« 



Gil of Cinnamon. 371 

sembles salicine. Forms fine silky needle-shaped crystals, 
having a bitter astringent taste. It is used as a febrifuge. 

X. Oil of Cinnamon (C 18 H 8 2 H) is obtained from cinna- 
mon bark by soaking it in a saturated solution of salt, and 
distilling. It is a heavy oily liquid, with the well known 
cinnamon odor and taste. This oil is supposed to be a hy- 
druret of a new radical called cinnamyle, C 18 H 8 2 , symb. Ci. 

Cinnaminic Acid (C 18 H 8 3 .HO) is formed by exposing oil 
of cinnamon to the air or to oxygen gas. It is a white crys- 
talline substance, resembling benzoic acid, and forms a simi- 
lar class of salts. Heated with sulphuric acid and bichro- 
mate of potassa, it is converted into benzoic acid. It exists 
also in the balsam of Tolu, from which it may be obtained 
by boiling this substance with an equal weight of hydrate of 
lime, and a large quantity of water. Oil of cinnamon and 
chlorine give rise to compounds of little importance. This 
oil is obtained from China and Ceylon ; the former is much 
the best ; both are impure. They may be purified by 
adding cold strong nitric acid, and decomposing the solid 
matter thus formed with water. 

XI. Oxide of Carbon, (Oxalyle.) C 2 2 . Oxide of carbon 
has already been described as carbonic oxide, page 172. To 
make it correspond to the termination which has been given 
to the compound radicals, it has received the name oxalyle, 
derived from oxalic acid. 

Oxalic Acid (C 2 3 HO) was discovered by Scheele, in 1776, 
and is found in several plants, among which is common sor- 
rel, the sour taste of which is caused by the presence of ox- 
alic acid ; it is obtained also by the action of nitric acid on 
• sugar. Many other organic substances, as starch, gum, most 
Df the other vegetable acids also, wool, silk, &c, are con- 
vened into oxalic acid by the action of nitric acid. 

Properties. Oxalic acid is sold in small, slender crystals, 



8K2 Organic Chemistry. 

and much resembles Epsom salts, for which it is sometimes 
mistaken with fatal consequences. But, although a power- 
ful poison, it may he tasted without danger, when its strong 
acidity will easily distinguish it ; if taken by accident, pow- 
dered chalk in water or magnesia should be administered. 

Oxalates of Potassa. There are three of these compounds, 
one of which, the Unoxalate, (HO.C 2 3 , KO.C 2 3 +2Aq.) 
is often sold under the name of essential salt of lemons, 
for removing the stains of iron-rust from linen ; a solu- 
tion of oxalic acid will answer the same purpose. Quad- 
roxalate of potassa is sold for the preceding, and is formed 
by dissolving the binoxalate in hydrochloric acid, and crys- 
tallizing. In this way the salt is manufactured on a large 
scale. 

Oxalate of Lime (CaO.C 2 Q 3 -f-3Aq.) exists in several spe- 
cies of lichen, and, when recently precipitated, is a snow- 
white flocculent powder. This salt may be distinguished 
from most other precipitates by its being insoluble in water, 
ammonia, and acetic acid, but soluble in nitric and hydro- 
chloric acids. On this account, lime may be detected in 
solutions from which all other metallic oxides have been 
separated: thus these oxalates are used to separate lime from 
magnesia. Lime may also be used to detect oxalic acid. 

XII. Cyanogen, syrnb. NC 2 , or Cy. equiv. 26.39. Cyanogen 
has already been noticed, (page 196.) It is easily obtained by 
heating in a glass retort the cyanide of potassium. A black 
substance remains in the retort, identical in composition with 
cyanogen, which has been called Para-cyanogen. 

Properties. Cyanogen is a colorless gas, with a strong 
pungent odor, and burning with a beautiful purple flame. It 
is characterized by the property of entering into combination 
with other bodies, like a simple substance. It is one of the 
compound radicals. Its compounds, which have been de- 



Cyanic Acid.- — Urea. 373 

scribed as cyanurets, are now generally classed with the ides, 
thus, cyanide of potassium, for cyanuret of potassium, &e. 

Cyanic Acid (CyO, HO=43.39) is formed by dissolving 
cyanogen gas in a solution of caustic potash. It is a trans- 
parent, highly volatile liquid, of a pungent odor, strongly 
affecting the eyes. It passes, soon after its formation, with 
the evolution of heat, into a substance called cyamelide, (C a 
O a , NH, Liebig.) 

Cyanate of Ammonia (C 2 2 N 2 H 4 ) is formed by ming- 
ling dry ammonia with the vapor of cyanic acid. It is a 
white crystalline salt, which, when heated, loses a little am- 
monia, and is converted into 

Urea. This substance exists as an animal product in 
urine, and was the first organic body which was formed arti- 
ficially. It may be obtained by evaporating fresh urine to a 
sirup, and acting upon it with strong nitric acid, decompos- 
ing the compound thus formed by an alkali", and purifying 
the urea with alcohol. It has the formula C 2 2 2NH 2 =Ur. 

Properties. Urea crystallizes in flattened four-sided prisms. 
It has a cooling taste like nitre, somewhat acrid and bitter, so- 
luble in its own weight of cold water. It fuses at 248°. Ex- 
posed to dry air, it is permanent, but deliquesces in damp 
air. It is a feeble base, uniting with acids. The nitrate of 
urea and the oxalate are the most important. The lactate 
of urea is the form it assumes in human urine, and the hip- 
puriate of urea in the urine of the cow. 

Fulminic Acid (Cy 2 2 ,2HO== 86.78) was noticed page 196, 
as isomeric with cyanic acid. The proportion of its elements 
are the same ; but it possesses quite different properties. It 
has never been separated from its salts, in consequence of its 
undergoing decomposition the moment it is liberated. 

It forms two classes of salts, one containing 2 equivalents 
of base as the fulminate of silver, (Cy 2 2 ,2AgO) and the other 
containing two bases as the fulminate of oxide of silver and 
potassium Cy a 2 AgO.KO. 



374 Organic Chemistry. 

All the salts of this acid are characterized by the property 
of exploding when heated or struck with any solid body. 

The fulminate of silver and the fulminate of mercury are 
used for percussion caps, torpedoes, &c. The former is the 
most dangerous to experiment with. 

it is easily formed by dissolving silver in dilute nitric 
acid, and adding pure alcohol to check the violence of the 
action. The process may be conducted in a glass tumbler. 
T^o white precipitate which is formed, must be poured on a 
filter, and allowed slowly to dry. It should then be placed 
in small paper boxes, and kept undisturbed in a cool place. 
Mercury may be used instead of the silver, and preserved 
in the same way. 

Exp. Take a small quantity of this salt on the point of a knife, place 
it in sand or small pebbles, and roll the whole up into paper balls. These, 
when thrown against the floor, will explode with a sharp report. The ex- 
plosion is due to the decomposition of the salt ; the solid being suddenly- 
resolved into the state of a gas. 

Cyanuric Acid (Cy 3 3 .3HO) may be formed by several 
processes, (see p. 196.) One of the best is to dissolve 
Melam in sulphuric acid, add 30 parts of water, and boil the 
whole, adding water for 4 or 5 days till the liquid does not 
give a white precipitate with ammonia. The liquid on cool- 
ing deposits crystals of cyanuric acid, which may be purified 
by re-crystallization. This acid is tribasic, forming three 
classes of salts, which are distinguished by the fact, that one, 
two, and three equivalents of water are displaced by some 
other base ; thus, the 

Acid has the formula, Cy 3 3 ,3HO. 

Cyanurate of Potassa, Cy 3 O s ,K02HO. 

Cyanurate of Binox, silver, Cy 3 O s ,2AgO.HO. 

Cyanurate of Terox, silver, Cy 3 3 ,3AgO. 
This acid differs in other respects, also, from the two pre. 
ceding, and particularly in a greater permanence of compo- 
sition. Cyanogen unites with chlorine, iodine, and bromine, 
forming unimportant compounds. (See page 197.) 

Hydrocyanic Acid, Prussic Acid, CyH. This remarkable 



Compounds of Cyanogen. 375 

substance has been described (page 197) as one of the most 
virulent of poisons. It is used in medicine for diseases of 
ihe chest and lungs. It is easily decomposed by exposure to 
jght, and should be kept in the dark. 

As this substance is sometimes used for poisoning, it is de- 
sirable to be able to detect it. 

The most delicate test is the following — 

1. Take the suspected liquid as the contents of the stom- 
ach, mix it with one-sixth of its bulk of sulphuric acid, and 
distil it. Add now to the distilled liquid a few drops of proto- 
sulphate of iron, and a slight excess of caustic potash to 
precipitate the oxide of iron. 

2. Take the alkaline liquid, and after exposing it to the 
air, to allow the peroxide of iron to form, add sufficient 
hydrochloric acid, to render it acid, when there will be formed 
the well known substance, prusssian blue — a sure test of the 
presence of hydrocyanic acid. 

Cyanogen unites with sulphur, forming several compounds. 

The compound described as bisulphuret of cyanogen, 
(page 208,) is supposed to be a substance composed of 
a hypothetical radical sulphocyanogen with sulphocyanic 
acid and water. The radical has the formula, Cy2S, or 
Symbol, Csy. 

Hydrosulphocyanic Acid, (S 2 CyH,) is described, p. 208. 

Su/phocyanide of Potassium, (CyS 2 K,) is formed by fu- 
sing 17 parts of dry carb. of potash, 32 of sulphur, and 46 of 
dry ferrocyanide of potassium in an iron retort. The mix- 
ture is stirred gently until bubbles of gas cease to escape, and 
the vessel has attained a dull red heat. By washing in water, 
the salt is dissolved, and by evaporation, crystallizes in long 
colorless prisms, having a sharp saline taste. 
• Cyanide of Potassium (CyK) is described page 233. 

Cyanogen also unites with zinc, cobalt, iron, mercury, pal- 
ladium, silver, and gold, forming cyanides of these metals, some 
©f which ha\ e already received attention, in other parts of 



376 Organic Chemistry. 

the work. With iron, cyanogen forms one of the hypotheti 
cal radicals called 

Ferrocyanogen, (Cfy.) which is supposed to unite with hy« 
drogen to form 

Hydro-Ferrocyanic Acid. Cy 3 Fe.H 2 . This acid is formed 
by the action of 1 part of hydrochloric acid on 4 parts of a 
saturated solution of ferrocyanide of potassium, and then di- 
gesting the mixture with 2% parts, dry measure, of pure ether, 
a white crystalline body rises to the surface with the ether, 
which, when purified with ether, and dried, is pure ferrocy- 
anic acid. 

Properties. This acid in solution has a powerfully acid 
taste, and decomposes readily alkaline carbonates. It unites 
with bases forming ferrocyanides . 

Ferrocyanide of Potassium (C 6 N 3 Fe.K0.3HO) is manufac- 
tured on a large scale under the name of yelloiv prussiate of 



Process. Impure carbonate of potash, iron filings, and dry 
refuse animal matter, are put into a large iron vessel, excluded 
from the air, and fused at a red heat. By this process, cya- 
nide of potassium is generated, and is dissolved out with hot 
water; the cyanide is thus converted by the oxide or the 
sulphuret of iron into the ferrocyanide of potassium. When 
this filtered solution is evaporated, crystals are formed, which, 
by resolution and evaporation, yield large yellow crystals, sol- 
uble in 4 parts of cold and in 2 of boiling water. It has a 
mild saline taste, and may be taken with impunity. 

Ferrocyanide of potassium is a valuable chemical reagent. 
When mixed with slightly acid or neutral salts of the metals, 
as of copper, lead, and iron, the potassium of the base is dis- 
placed by these metals, and forms compounds of characteristic 
colors. With any salt of the peroxide of iron, it forms ordi- 
nary Prussian blue, or 

Ferrocyanide of Iron. Cy 9 Fe 7 . This salt is well known 
as a beautiful blue pigment; dissolved in oxalic acid, it con- 
stitutes blue ink. 

By passing chlorine gas through a solution of ferrocyanide 



Mellone and Us Compounds. 377 

of potassium, a persalt of iron is precipitated, and the solu 
tion, by evaporation, yields beautiful dark red prismatic crys- 
tals of ferridcyanide of 'potassium, which is supposed to con- 
tain a radical called ferridcyanogen. Cy 6 Fe 2 or Cfdy, 

Cyanogen unites with cobalt and platinum, forming a se- 
ries of salts, having each a hypothetical radical, Cobaltocy- 
anogen, (Cy 6 Co 2 =Chy) and platinoeyanogen (Cy 2 Pt.=Cpy.) 

XIII. Mellone. C°N 4 =M1. 

When chlorine acts on sulphocyanide of potassium in so- 
ution, a yellow substance is precipitated, which has been 
sailed Metasulphocyanogen C 12 N 6 S 12 H 3 (Parnell.) 

By heating this substance, several substances are driven 
ofi^ such as sulphuret of carbon, sulphur and water, and 
there remains a yellow powder, which has the composition 
C 8 N 4 , and has received the name olmellon or mellone. 

It is insoluble, and is decomposed by a bright red heat 
into 3 vols, of cyanogen and one of nitrogen. It is one of 
the salt radicals combining with hydrogen, potassium, &c. 

Hydromellonic Acid (C 6 N 4 H or M1H) is formed by the ac- 
tion of hydrochloric acid on a hot solution of mellonide of 
potassium. On cooling, a white powder subsides, having 
strongly marked acid properties. 

Mellonide of Potassium (C 6 N 4 K or M1K) is formed by de- 
composing acetate of potash with hydromellonic acid, and 
washing the crystals thus formed with alcohol. The sulpho- 
cyanide is dissolved, and the mellonide of potassium remains, 
forming with water small needle-shaped crystals of a bitter 
taste. 

Melam (C 12 N n H 2 ) is formed by decomposing sulphocya- 
nide of ammonia by heat. It is a grayish-white powder. 

Melamine (C 6 N 6 H 6 ) is formed by boiling melam in a so- 
lution of 1 part of hydrate of potash and 20 of water, until 
the turbid liquor becomes perfectly clear. On cooling, mel- 
amine is deposited in transparent colorless or slightly yellow 



878 Organic Chemistry. 

crystals of the form of rhomboidal octohedrons. ' It forms 
salts with dilute aeids. 

Ammeline (C 6 N 5 H 6 2 ) remains in the solution when mela 
mine crystallizes, combined with potash, and is obtained by 
the action of acetic acid, and then by dilute nitric acid, form- 
ing nitrate of ammeline ; the ammeline is then precipitated 
by carbonate of ammonia. It forms very brilliant silky nee 
dies, and unites with the more powerful acids to form salts. 

Ammelide (C 12 N 9 H 9 5 ) is produced where melam, mela- 
mine, or ammeline, are decomposed by concentrated acids. 
It is a white powder, insoluble excepting in strong alkalies 
or acids. 

XIV. Uric Acid (Lithic Acid) C 10 N 4 H 4 O 6 exists in the 
urine of all carniferous animals. Guano, which exists in 
such abundance on many small islands, near the coast of 
Peru and Chili, and which is so extensively used as manure, 
is mostly urate of ammonia. It results from the decomposi- 
tion of the excrements of aquatic birds. Urinary calculi are 
often composed of it. Uric acid may be prepared from the 
excrements of serpents, as that of the boa constrictor, by dis- 
solving them in caustic potash, and decomposing the urate 
of potassa thus formed with hydrochloric acid. It crystal- 
lizes in thin silky scales of brilliant whiteness, inodorous and 
nearly insoluble in cold water. It unites with the alkalies 
and alkaline earths, forming sparingly soluble salts. Uric 
acid is supposed to be composed of a salt radical called Urile 
=l J "\ which radical contains the elements of cyanogen and 
oxide of carbon (2Cy.4CO or C 8 N 2 4 ) by adding 1 eq. of 
urea (C 2 2 N 2 H 5 ) to this, it will give the formula of uric acid 
(C 10 N 4 O 6 H 4 .) By the action of oxidizing substances upon 
uric acid, a very remarkable class of compounds are formed. 
By boiling this acid with peroxide of lead, a new compound 
is form A, called 

All ji join. C 4 N 2 H 3 3 . This substance is found in the 









Alloxan, — Murexide. 379 

illontoic fluid of the cow, and may be obtained in brilliant 
colorless prisms, by evaporating this fluid to one quarter of 
its bulk. (See Graham's Chemistry.) By adding uric acid 
gradually to nitric acid, sp. gr. 1.35, another compound, 

Alloxan (C 8 N 2 O 10 H 4 ) is formed. This substance crystal- 
lizes in large octohedrons with a rhombic base, very soluble 
in water, reddens vegetable blues and gives a purple stain to 
the skin. By the action of alkalies it forms alloxanic acid 
(ON 2 HO\) 

Alloxantin (C 8 N 2 H 5 10 ) is still another product of the de 
composition of uric acid by nitric acid. It is also formed by 
the action of sulphuret of hydrogen on alloxan. It crystal- 
lizes in obtuse four-sided prisms, which become red in am- 
moniacal air, and acquire a green metallic lustre. Allox- 
antin is decomposed into several compounds by the action of 
sulphuret of hydrogen. 

Murexide (C 2 N 5 H 6 8 ) is formed by u evaporating a solu- 
tion of uric acid in dilute nitric acid, until the solution ac- 
quires a flesh-red color." After cooling to 110°, ammonia is 
added, the whole diluted with half its bulk of water and 
cooled. 

Properties. Murexide forms crystals which are of a gar- 
net-red color, by transmitted light. By heating this sub- 
stance in caustic potash till the blue color disappears, and 
adding an excess of dilute sulphuric acid, 

Murexan (C fi N 2 H 4 5 ) is formed, called also -purpuric acid. 
It crystallizes in plates which have a very brilliant silky 
lustre. Murexan resembles uramile, and possibly may be 
identical with it. 

We have given the most important of the cyanogen series 
of compounds. For more extended details, the student is 
referred to Graham's Chemistry. 



380 Organic Chemistry. 

Section III. Organic Acids. 

Organic Acids are, for the most part, less liable to spon- 
taneous decomposition than other organic substances, although 
none of them can exist at the temperature of a red heat ; 
they all contain carbon and oxygen, most of them hydrogen ; 
generally they have more oxygen than would be sufficient 
to form water by combination of their hydrogen, but a few 
have these elements in the same ratio as in water. 

Malic Acid. C 8 H 4 8 ,2HO. This acid is contained in 
grapes, currants, gooseberries, oranges, apples, and in most 
of the acidulous fruits. It is also obtained by the action of 
nitric acid on -§• of its weight of sugar ; it forms salts with 
metallic oxides, called violates. 

Citric Acid. C 12 H 5 O u ,3HO. This acid is also found in 
many acidulous fruits, especially in limes and lemons, from 
which it is usually obtained. It has an agreeable flavor, and 
is an excellent substitute for lemons ; it is used in the prep- 
aration of lemon syrup, in which, however, tartaric acid is 
largely employed, being much less expensive, but of very 
inferior flavor. 

Aconitic Acid, (C 4 H 2 3 ,HO,) is formed by heating citric 
acid to a temperature of about 300°. It is also obtained 
from Aconitum napellus and Equisetumjiuviatale. It forms 
small confined crystals, soluble in alcohol, and by the action 
of dry hydrochloric acid upon its alcoholic solution, formj 
Aconitic Ether. When rapidly distilled it forms two iso 
meric bodies, itaconic and citraconic acids. 

Tartaric Acid. C 8 H 4 O 10 ,2HO. This acid also exists in 
acidulous fruits, usually in combination with lime or potassa. 
Tartaric acid is used with the bicarbonate of soda for an 
effervescing drink ; it forms numerous salts, many of which 
are double. 

Bitartrate of Potassa. In an impure form, this is knowr, 
by the name of crude tartar, and is found incrusted on the. 



Tartar Emetic — Tannic Acid. 381 

sides of wine casks, colored by the wine ; when purified it 
is white, and is known by the name of cream of tartar. It 
is used for the preparation of tartaric acid, and as a med- 
icine. 

Tartrate of Antimony and Potassa. This compound is 
sold under the name of tartar emetic, and is prepared by boil- 
ing sesquioxide of antimony with cream of tartar. It is neu- 
tralized by vegetable astringents, as tea or Peruvian bark, 
which may therefore be used as an antidote, in case of taking 
a too powerful dose. It is a white solid, slightly efflores- 
cent, and is composed, according to Philips, of 1 atom of 
bitartrate of potassa, 3 sesquioxide of antimony, and 3 of 
water. 

Tartrate of Potassa and Soda is prepared by saturating 
an excess of acid in tartar, with carbonate of soda. It has 
long been used in pharmacy under the name of Rochelle Salt 
and Sel de Seignette. It consists of 1 atom of tartrate of 
potassa, 1 atom of tartrate of soda, and 10 atoms of water. 
By the action of heat, tartaric acid loses successive portions 
of water, and two new acids are formed, the 

Tartrelic and Tartralic Acids, and when subjected to de- 
tractive distillation, it yields two other acids, the 

Liquid Pyrotartaric. C 6 H 3 5 ,HO. And 

Solid Pyrotartaric. C 5 H 3 O a HO. 

Paratartaric or Racemic Acid, (C 4 H 2 5 HO,) exists in cer- 
tain wines, or in the cream of tartar which is found in them. 
It is a more powerful acid than tartaric, and forms a class of 
salts, similar in composition to the salts of tartaric acid. Its 
decomposition by heat, produces also several new acids. 

Tannic Acid, or Tannin. C 18 H 8 12 . This substance ex- 
ists in gall-nuts, (the excrescences of several species of the 
oak,) in the bark of most trees, in tea, and in most vegetable 
astringents, and is the cause of their astringency. With 
gelatin or glue, it forms an insoluble compound, which is the 
basis of leather. Hence leather is prepared by soaking 



382 Organic Chemistry. 

skins in water, which contains ground bark, the tannic acid 
of which is taken in solution by the water. 

Exp. To a strong solution of gelatin (common glue answers well 
enough) add a strong infusion of gall-nuts ; a white precipitate will be 
formed, and may be collected upon a glass rod and pressed together, 
forming a strong extensible mass, resembling new leather. When exposed 
to the oxygen of the air, it is gradually converted into gallic acid. 

Gallic Acid. C 7 H 3 5 . This acid also exists in gall-nuts 
and in the bark of trees, but is more abundantly obtained by 
the oxidation of the tannic acid of gall-nuts. Common ink 
owes its color to the compounds of tannic and gallic acids 
with the sesquioxide of iron, and may be extemporaneously 
prepared by adding to an infusion of gall-nuts a solution of 
copperas, which has been exposed to the air.* 

Some of the most important of the remaining organic 
acids are the following : — 

Mellitic Acid, (C 4 3 .HO,) is contained in the rare sub- 
stance called, honey-stone. It exists as a white, slightl) 
crystalline powder, soluble in alcohol ; and, by boiling the 
solution, there seems to be formed an acid — mellitate of ether. 
It forms salts called mellitates. 

Croconic Acid (C 5 4 ) is a yellow, easily crystallized solid, 
soluble in water and in alcohol. All its salts are yellow. 

Lactic Acid, (C 6 H 5 5 ,) so called from being first noticed in 
sour milk, was discovered by Scheele, in 1780. It has since 
been found in several vegetable bodies when left to sponta- 
neous fermentation. It is colorless, without smell, but ex- 
cessively sour. Its salts are termed lactates. 

Kinic Acid (C 14 H n O".HO) exists in cinchona bark, in 
combination with lime, quinia, and cinchonia. 



* A very good ink may be formed thus : Take 8 oz. of bruised galls 
4 oz. sulphate of iron, 3 oz. gum arabic, and 1 oz. of sugar candy. Boi ? 
the galls in 6 qts. of water until but 3 qts. remain ; strain, and add the 
other ingredients, stirring the whole till dissolved. 

Ink may be kept from moulding by keeping a few cloves in the bottle. 
Common writing ink is much more permanent, if Indian ink — which i* 
lampblack made into a cake with isinglass — is dissolved in it, 1 oz. to 3 
qts. of ink. 



Succinic, Oleic, Crenic Acids. 

Meconic Acid (C I4 HO u .3HO) is found in the poppy, in 
combination with morphia, and crystallizes in white, trans- 
parent scales. 

Pyromeconic Acid. C 10 H 3 O 5 .HO. 

Comenic Acid (C 12 H 2 3 .2HO) is obtained from the meconic 
by boiling its aqueous solution. 

Pyrogallic Acid (C 6 H 3 3 ) is obtained by heating gallic 
acid to 419°. 

Metagallic Acid (C 12 H 3 3 ) is formed by heating gallic acid 
to 480°. 

Ellagic Acid (C 7 H 2 4 ) is very similar to the preceding. 

Succinic Acid (C 4 H 2 3 HO) exists in amber, and is obtained 
by the aid of heat. It is obtained in three states: — 1. Com- 
bined with an atom of water, which, when pure, is the crys- 
tallized acid of the shops. 2. With % an atom of water, pro- 
duced by keeping the crystallized acid for a long time be- 
tween the temperatures of 260° and 284°. 3. Anhydrous. 
The compounds which this acid forms with bases are termed 
succinates. 

Moroxylic Acid is found, in combination with lime, on the 
bark of the white mulberry. 

Oleic Acid (C 44 H 39 4 ) is obtained from the soap made from 
linseed oil and potassa. It burns like the fixed oils, and forms 
salts, or soaps, called oleates. When olive oil is mixed with 
half its weight of concentrated sulphuric acid, three acids are 
formed, one of which has been called sulpho-oleic ; and this, 
when decomposed, affords hydro-oleic acid. 

Crenic Acid (108) was discovered by Berzelius, in 1832, 
in the water of Porla well, in Sweden. It is inodorous, a 
sharp, followed by an astringent taste, yellow and transpa- 
rent; very soluble in water and in alcohol. When the solu- 
tior is exposed to the air, apocrenic acid is formed. Its salts 
are termed crenates, and resemble extracts in appearance, 
but are incapable of crystallizing. 

Apocrenic Acid (132) was obtained by digesting the ochre 



384 Organic Chemistry. 

of Porla well with potassa, and precipitating the acid by means 
of acetate of copper. The apocrenate of copper falls, from 
which the acid is separated by the action of hydrosulphuric 
acid, absolute alcohol, and potassa. It is a brown substance, 
resembling a vegetable extract. Crenic and apocrenic acids 
have been detected in many waters, and in the vegetable 
mould of soils. 

Section IV. Vegetable Alkalies. 

The existence of vegetable alkalies was not known until the 
present century, and very little attention was given to them until 
1816. They all contain nitrogen, and unite with acids to-form 
salts, in which state they are found in the vegetable kingdom. 
These salts exactly resemble those of metallic oxides. They 
possess other properties, which prove their alkaline character. 

The method of preparation is nearly the same for all of 
these alkalies ; the substance which contains one of them is 
steeped in a large quantity of water, which dissolves the salt 
that contains it ; the solution is boiled for a short time with 
lime or magnesia, and the vegetable alkali is set free in an 
insoluble state, and may be collected on a filter with the lime ; 
if then boiled in alcohol with powdered charcoal, it is dis- 
solved by the former, and purified by the latter ; then, by 
filtering while hot, it is separated from the charcoal, and the 
lime with which it was mixed ; it is deposited from the alco- 
hol on cooling, by evaporation. 

Morphia. C 34 H 20 NO 6 =284. This alkali is the narcotic 
principle of opium, in which it is combined with sulphuric 
and meconic acids, and is associated with several other vege- 
table alkalies, and with gummy, resinous, and coloring mat- 
ters. Opium contains about nine and a half per cent, of mor- 
phia ; when pure, it is very insoluble in water, and conse- 
quently but little poisonous ; but when in the state of a salt, 
as in opium, it is a very powerful poison ; one half a grain in 
solution will produce alarming effects on the animal system. 



Vegetable Alkalies. 385 

When opium has been administered as a poison, the presence 
of its morphia may be detected by a process too elaborate to 
be inserted here. A skilful chemist will detect a single grain 
of morphia in 700 grains of water. Some of the salts of mor- 
phia are useful as medicines ; of which the hydrochlorate and 
acetate are the principal. 

Narcotina (C 48 H 24 N0 16 ) was discovered by Desrone, in 
1803, and is obtained from opium ; it is a white substance, 
and may be taken into the human stomach without sensible 
effects, but it is speedily fatal to dogs. 

Cinchonia (C 20 H 12 NO) and Quinia, (C 20 H 12 NO S =162.) 
These two alkalies were detected by Pelletier and Caventou, 
in 1820, in Peruvian bark, and impart to it its value as a med- 
icine. Cinchonia is found in the pale bark j quinia, with a 
little cinchonia, in the yellow bark ; and both in the red bark. 
Cinchonia is insoluble in cold water, and nearly so in hot 
water ; in boiling alcohol it is freely dissolved, and the solu- 
tion has an intensely bitter taste ; some of its salts are solu- 
ble in water. 

, Quinia, or Quinine, is also almost insoluble in water, but 
with alcohol forms an intensely bitter solution. 

Quinia forms several salts, one of which, the sulphate, is 
manufactured in large quantity for medical purposes, and is 
commonly sold by the name of quinine. It is soluble in al- 
cohol, or slightly in pure water, and freely if the water is 
slightly acidulated by sulphuric acid ; the solution, although 
containing but a minute portion of quinia, is intensely bitter. 

On account of its high value, sulphate of quinia is often 
adulterated with gum, starch, sugar, magnesia, and various 
other substances ; gum and starch are insoluble in alcohol, 
and may be detected by dissolving the suspected quinia in 
boiling alcohol. Sugar may be detected by adding pearlash 
to the solution in water, when the quinia will be thrown 
down, and the sweet taste may be perceived ; magnesia will 
be left after burning a portion of the adulterated article. 

17 



386 Organic Chemistry, 

Strychnia (C 44 H 23 N 2 4 ) was discovered in 1818, by PeLe. 
tier and Caventou. This remarkable alkali is found in the 
nux vomica and in the upas-tree. It is freely soluble in alco- 
hol, and but slightly so in water ; although nearly insoluble 
in the latter, the minute portion which is taken up, commu- 
nicates to the water the most intense bitterness; a single 
grain of strychnia will render eight gallons of water bitter. 
It is one of the most virulent poisons yet discovered ; half a 
grain in the throat of a rabbit occasioned death in five min- 
utes. Its action is always accompanied by symptoms of 
locked-jaw. 

Emetia. This alkali constitutes 16 per cent, of ipecac- 
uanha, and appears to be the sole cause of its emetic prop- 
erties. 

Sanguinaria is a peculiar alkali, discovered, by Mr. Dana, 
in the Hood root, (sanguinaria Canadensis.) Its salts have a 
red color. 

Nicotina is the peculiar principle of tobacco ; it is a viru- 
lent poison. 

Codeia, (C 35 H 20 NO 5 ) discovered in 1832, by Robiquet, in 
the hydrochlorate of morphia. When taken into the stomach 
in doses of from 4 to 6 grains, it produces an excitement sim- 
ilar to intoxication, followed by depression, nausea, and vom- 
iting. 

Brucia (C 44 H 25 N 2 7 ) resembles strychnia, and may be 
procured from the nux vomica. It is intensely bitter, less 
poisonous than strychnia, but similar in its effects. 

Conia (C 12 H 14 NO) is the active principle of conium-macu* 
latum, or hemlock, and is the most virulent poison k'aown, 
with the exception of hydrocyanic acid. 

Parilla, or Parillina, exists in the common sarsapaiiila of 
commerce. Its color is white, taste sharp and bitter, and; 
when swallowed to the extent of 13 grains, produces nausea, 
vomiting, diminishes the rapidity of the circulation, and acts 
as a sudorific. 



Fixed Oils. — Glycerine. 387 

Section V. Oils and Fats. 

The oils are divided into fixed and volatile oils. The for- 
mer are not much affected by a heat which does not decom- 
pose them, while the latter rapidly pass away in vapor. The 
greasy stain of the former on paper, or any other surface, is 
permanent ; that of the latter soon disappears. 

1. Fixed Oils. The fixed oils are usually obtained from 
seeds; as the almond, linseed, and poppy-seed. Olive oil, 
however, is extracted from the pulp around the stone. The 
density of these oils is less than water, varying from .9 to 
.96. They are solid at a low temperature. They burn 
with a clear, white light. By exposure to the air, they be- 
come rancid, and at length viscid. In this change, oxygen 
is absorbed ; and the oil itself probably undergoes some 
change, although it has been supposed that rancidity was 
caused by the acidification of some mucilage present. By 
heating the oil in open vessels, it acquires the property of 
drying rapidly ; in which process much oxygen is absorbed, 
and carbonic acid and hydrogen given off. Drying oils are 
used for paint, and, when mixed with lampblack, constitute 
printers' ink. Drying oils sometimes absorb oxygen so 
rapidly as to set fire to combustibles. Spontaneous com- 
bustion often occurs where cotton has been moistened with 
them. 

By means of mucilage or sugar, the fixed oils may be 
permanently suspended in water. Such a mixture is called 
an emulsion. With ammonia, they form a soapy liquid 
called volatile liniment, which is a direct compound of oil 
and the alkali. The fixed alkalies have a similar action m 
the cold, but, when heated, soap is generated. When acted 
upon by alkalies, with the aid of heat, they are separated 
into acids, which combine with the alkalies to form soaps, 
and into another compound, called 

Glycerine. C 8 H 7 6 ,HO. This substance is easily formed 



388 Organic Chemistry. 

by heating a mixture of olive, or some other oil, oxide of 
lead, and water ; an insoluble soap of lead is formed, and a 
sweetish substance is separated by the water, which appears 
to act as the base of the oil, the acid of which combines with 
the lead. The solution is acted upon by sulphuret of hydro- 
gen, with the addition of animal charcoal, filtered and evap- 
orated in vacuo. 

Properties. When pure, glycerine is a viscid liquid, sp. 
gr. 1.27, very sweet taste, soluble in water, volatizes in part 
when exposed to heat, and is converted by the action of nitric 
acid into oxalic acid. It forms a compound acid with sul- 
phuric acid, the Sulpho-glyceric acid, C°H 7 5 ,2S0 3 . 

When glycerine is heated with any body having a strong 
affinity for' water, a new compound is formed having the 
peculiar pungent odor of burnt fat, called Acroleine, C 6 H 4 2 . 
Glycerine is combined with several acids, giving rise to 
Stearine, Margarine, and Oleine. 

Stearine exists in tallow, from which it may be separated 
by means of hot ether. It is a white crystalline solid. By 
the action of caustic alkalies, 

Stearic Acid (C 68 H 66 6 ,2HO) is separated from the gly- 
cerine. This acid is insoluble in water, but very soluble in 
alcohol and ether, fuses at 167°, and possesses distinct acid 
properties. It unites with the alkalies, and forms soaps, all 
soluble in water; v/hile the stearates of the metallic oxides 
are insoluble. 

Margarine exists, also, in many fats, and is obtained by 
evaporating the ethereal solution, and absorbing the oil with 
blotting-paper. It differs but slightly from stearine, and 
when acted upon by alkalies, it yields glycerine, and 

Margaric Acid, (C 68 H 66 6 ,2HO,) a substance very anal- 
ogous to stearic acid, containing only one eq. of oxygen less, 
and forming similar salts, the margarates ; melts at 140°, and 
when digested with nitric acid it yields suberic and succinio 
acids, and several other products. 



Palm Oil— Olive Oil 389 

Oleine is a white combustible liquid, lighter than water, 
obtained from olive oil by means of cold, which causes the 
margarine to crystallize. By the action of alkalies it also 
yields glycerine, and 

Oleic Acid. C 36 H 33 3 ,HO. This acid is obtained from the 
soap made of linseed oil and potassa. It is combustible, and 
resembles oleine in its properties, rapidly absorbing oxygen 
from the air, and uniting with alkalies and forming soaps. 
When heated it is decomposed into 

Sebacic Acid. C 10 H 8 O 3 ,HO. 

Palm Oil, which is used extensively in the manufacture 
of yellow soap, is obtained by boiling and pressing the 
fruits of the elais guianensis, growing in Africa. It is of the 
consistency of butter, has an orange-red color, with an aro- 
matic odor. It is a mixture of oleine and palmatine. The 
soap formed by this oil with alkalies, when decomposed, is 
found to contain a new acid, called 

Palmitic, (C 32 H 31 3 ,HO,) which is similar to the margaric 
acid in appearance, and fuses at the same temperature, 140°, 

Cocoa Oil, which is extracted from the kernel of the cocoa- 
nut, is a white substance, consisting of oleine and a solid fatty 
matter used for making candles. By the action of alkalies 
we obtain a peculiar fatty acid, the 

Cocinic Acid. C 37 H 26 3 . 

Olive Oil is extracted from the fruit of the common olive, 
(Olea Europea,) and is used as an article of luxury. When 
mixed with nitrous acid, it yields a fatty crystalline body 
called Elaidine, and this body by saponification gives rise to 
Elaidic Acid, C 7S H 66 5 . 

Croton Oil is obtained from the croton tiglium of the East 
Indies, and possesses powerful purgative properties. It is 
used in medicine. 

Train Oil is obtained from the blubber of the right whale, 
and is much inferior for lights to spermaceti. 

Spermaceti is obtained from the blubber of the sperm 



390 Organic Chemistry. 

whale, and from a large cavity in the head, from which 
twelve or fifteen barrels of liquid oil are sometimes dipped 
out. This substance is strained through stout bags, which 
are subjected to a strong pressure. The solid which remains 
is spermaceti, of which candles are manufactured, and the 
liquid is the spermaceti oil. As the oil is more liquid in hoi 
weather, summer strained oil contains more spermaceti, and 
a given quantity will therefore produce more light, and burn 
less freely than winter strained oil ; the latter is usually pre- 
ferred, as giving a clearer light, and as being less affected by 
cold, but it is much less economical. 

Hog's Lard and Suet are well-known substances, differing 
much in respect to their point of fusion. A very good oil 
has been obtained from hog's lard, by pressing it in strong 
bags. It is nearly equal, for giving a white clear light, to 
sperm oil. 

Soaps. When any of the animal or vegetable oils or fats 
are boiled with a solution of potassa or soda, they are con- 
verted into oleic, margaric, or stearic acids, and another 
principle, glycerine ; the acids unite with the alkalies and 
form soaps. All the various kinds of soap have a similar 
constitution. Soft soaps are formed from fat and potassa ; 
hard soaps contain soda as their base. They are soluble in 
water, and are extensively used in the arts and in culinary 
operations ; but when lime, oxide of lead, and many other 
metallic compounds, are mixed in solutions of soap, the acids 
combine in preference with these oxides, and form insoluble 
compounds; hence, hard water, containing salts of lime, cur- 
dles soap. 

Butter consists of a solid crystalline fat, an oil, a yellow 
coloring matter, and a little caseine, which latter substance 
does not belong to its constitution. The oil is a mixture of 
oleine, and a fatty substance, lutyrine, which by the action 
of alkalies, forms soaps ; and these, when decomposed, are 
found to contain three acids, hutyric, capric, and caproic acids, 



Volatile or Essential Oils. 391 

Butyric Add (C 8 H 7 0, 3 HO) has a sour taste, and an odor re- 
sembling rancid butter. It is a colorless, oily liquid, sp. gr. 
.976, soluble in water, and has lately been formed by the 
fermentation of starch. The other acids are very similar to 
butyric, but are less soluble in water. 

Wax. The various kinds of wax, such as bees-wax, 
myrtle-wax, and cowtree-wax, are regarded as similar in 
composition with fats, and are classed by some chemists with 
them. 

Ambergris, found floating on the surface of the ocean, is 
supposed to be a concretion formed in the stomach of the 
sperm whale. 

2. Volatile or Essential Oils. The flavor of aromatic 
plants is owing to the presence of volatile oils, which are 
obtained by distillation. Water must be added to the plants 
to keep them from burning. Some, however, are obtained 
by expressing the rinds of certain fruits, such as the orange, 
lemon, bergamot. Although usually of an agreeable odor, 
those oils have an unpleasant, acrid taste ; but, when diluted, 
some of them have an agreeable taste. They are but slight- 
ly soluble in water, and are freely dissolved in alcohol. 
Such solutions are commonly sold under the name of es- 
sences. Like the fixed oils, they burn with a clear, white 
light. They have the property of dissolving sulphur, and 
the solution is called balsam of sulphur. 

A few of these oils — as the oil of turpentine, of lemons, 
and of copaiva — contain only carbon and hydrogen ; others 
contain oxygen also. A few contain one or more additional 
elements, as sulphur and nitrogen. 

The principal volatile oils are, oil of turpentine, lemons, anise, junipet, 
camomile, caraway, lavender, peppermint, rosemary, camphor, cinnamon, 
cloves, sassafras, mustard and bitter almonds. 

Common Spirits of Turpentine consists of resin dissolved 
in the oil of turpentine — which last may be obtained by dis- 
tillation- 



392 Organic Chemistry. 

Camphor is a volatile oil, solid at common temperatuies, 
On account of its toughness, it is pulverized with difficulty, 
unless a few drops of alcohol are added. It is insoluble in 
water, but is freely soluble in alcohol. Artificial camphor 
may be formed by passing a current of hydrochloric acid gas 
through oil of turpentine or oil of lemons. Camphor is very 
offensive to insects, which are prevented from devouring cab- 
inets of natural history, collections of birds, insects, etc., by 
placing pieces of camphor in the cases. 

Resins. Resins are the concrete juices of plants, solid, 
brittle, and without taste ; they are good non-conductors of 
electricity, and, by friction, become negatively electrified; 
they are easily melted, and burn with a yellow flame and 
dense •'smoke. They are soluble in alcohol, ether, and the 
essential oils, but are quite insoluble in water. 

Common Resin is procured by heating turpentine ; the vol. 
atile oil is expelled, and resin remains. It is a mixture of 
pinic acid (C 20 H 15 O 2 ) and sylvic acid (C 40 H 30 O 4 .) 

Turpentine is the juice of several species of pine-trees. 
Other resins are : copal, lac, mastic, and dragon's blood. 

Copal is the most important, and is used for varnish. In- 
dian ink is a solution of borax, lac, and lampblack. 

The uses of resin are various. Dissolved in oil or alcohol, 
and diluted with spirits of turpentine, they form various kinds 
of varnish. Sealing-wax is made of lac, turpentine, and com- 
mon resin. It is colored red with cinnabar or red lead, 01 
black with lampblack. 

The soot, which is procured from the combustion of res- 
inous wood, turpentine, or resin, is lampblack. When tur- 
pentine is extracted by heat, it is partially changed, and be- 
comes tar. When tar is thickened by boiling, it becomea 
pitch. 

Amber is a fossil substance, consisting of a peculiar bitu* 
minous matter and resin ; it often contains insects. 

Balsams are the juices of some kinds of trees. Some are 



Gum Resins. — Wax. 393 

fiolid, others are liquid. They are composed of resin and 
benzoic acid. 

Gum Resms are the hardened juices of certain plants, con* 
sisting of resin, gum, and volatile oil. Their proper solvent, 
therefore, is a mixture of alcohol and water, or common spir- 
its. They are numerous, and many of them are valuable 
medicines ; among them are aloes, assafoetida, galbanum, gam- 
boge, myrrh, and guaiacum. 

Caoutchouc, or India rubber, is obtained from four species 
of trees, two of which grow in South America, and two in 
the East Indies. It is usually black, but when not darkened 
by smoke, is of a whitish color. It burns with a bright flame ; 
is insoluble in water or alcohol. It is soluble in ether, the 
essential oils, etc. If a bag of it be soaked in etheV, it will 
become soft and gelatinous before dissolving, and in that 
state may be blown out into a very large and thin bag. The 
most useful solvent of caoutchouc is a dark, volatile liquid, 
obtained by the careful distillation of caoutchouc itself; aboUi 
four-fifths of the solid pass over in this liquid form. 

Wax. Wax is found in the pollen or dust of flowers, on 
some leaves as a kind of varnish, and especially on the ber- 
ries of the wax plant, (myrica cerifera.) As bees deposit wax, 
when fed only on sugar, beeswax is an animal product. Wax 
is insoluble in water, and is sparingly dissolved by alcohol 
and ether. It is composed of two principles, cerine and 
myricine. 

Creosote. This substance exists in tar, and in pyroligne- 
ous acid. It is a colorless, oily liquid, with an odor like 
smoked meat. It has a burning taste, followed by sweetness. 
Its most remarkable property is that of preserving meat. The 
antiseptic properties of smoke, and crude pyroligneous acid, 
appear to be owing to this substance. It is soluble in 80 
parts of water, and freely in alcohol. Insects and fish are 
killed by the aqueous solution. It is said to be useful as a 
sure for toothache, ulcers, etc. 

17* 



H94 Organic Chemistry. 



Section VI. Coloring Matters. 

The most common colors in the vegetable kingdom are 
green, yellow, blue, and red. The greater part of the infinite 
diversity of colors consists of different shades or mixtures of 
these. The coloring matter of plants is usually diffused 
through other proximate principles. All vegetable colors 
are destroyed by chlorine, and usually changed by acids or 
alkalies. 

Lakes are insoluble compounds of coloring matter with 
alumina, or oxide of iron or of tin. 

Process. Dissolve alum in a colored solution, and, on add- 
ing an alkali, (as potassa,) alumina will be precipitated ; and, 
at the moment of separation from the alum, will combine with 
the coloring matter. 

In dyeing, some colors have a sufficient affinity for the 
fibre of the cloth to remain fast on a mere immersion of it. 
In many cases, however, this is not sufficient, and the color 
would be removed by washing. A third substance is intro- 
duced, which, havi-g an affinity both for the coloring matter 
and the cloth, fixes the former permanently to the latter. 
This third substance is called the mordant or basis : those 
which are in common use are, alumina in alum, oxide of 
iron in copperas, and chloride of tin, which is converted into 
„he oxide. All the colors of dyed stuffs are produced from 
the four — blue, red, yellow, and black. 

Blue Dyes. Indigo is the most important of these, and is 
obtained from several species of a genus of plants which are 
cultivated in America and Asia. The plants are fermented 
and beaten in water, at the bottom of which the indigo sub- 
sides. Common indigo contains, in addition to its peculiar 
blue, a red and a brown coloring matter, with some gluten. 
Pure indigo sublimes at 550° Fahr., and condenses in acic- 
ular crystals. It is insoluble in water, and but slightly solu« 



Indigo. — Isaiiue. 3tf$ 

ble in boiling alcohol ; k is soluble in sulphuric acid. If in- 
digo be put into a lube with three times its weight of green 
vitriol, and an equal quantity of slacked lime, with water, the 
protoxide of iron will be precipitated by the lime from the 
ijreen vitriol, and the indigo will be de-oxidized by it, and 
become yellow. Dyers dip their cotton cloth into it in this 
condition, and by exposure to air the doth becomes perma- 
nently blue, 

Pure Indngo is composed of C^EPNO 2 , but when exposed 
to deoxidizing agents as above, it is reduced, and becomes 
wlufc, having the formula C ir H 3 N0 2 ,H. 

When indigo is heated with dilute chromic acid, or SO 3 , 
and bichromate of potassa, it forms a yellow solution, which, 
on evaporation, deposits orange-red crystals of 

Isatine., (C'TPNO 4 ,) containing two additional equiv. of 
■oxygen. By the action of alkalies, isatine takes up the ele- 
ments of water, and forms 

hatinic Acid, (C 16 H 6 NO s ,) and this acid by the action of 
chlorine, forms two peculiar substances, called cJilorisatine. 
(C 16 H 4 N0 4 C1,) and hichlorisaiine. (C 16 H 3 N0 4 C1 2 .) And by 
the continued action of chlorine on these latter substances, a 
volatile substance in crystalline scales, of a brown-yellow 
color, is formed, called Cldoranile, (C 6 C1 2 2 ,) which by the 
action of potash, gives rise to chloride of potassium, and 
Cldoranilate of potash. From this latter substance Chlora- 
mlic Acid (C°Clo 3 ) may be obtained, as a reddish powder. 

By transmitting sulphuret of hydrogen through an alcoholic 
solution of chlorisatine, a white compound is formed, called 
Chlorisatyde. 

By the continued action of nitric acid, upon indigo, anilic, 
91 indiirotic acid, (C u H 4 N0 9 ,)'and carbazotic or picric acid, 
(C 12 H 2 N 3 13 ,) are formed. The former forms colorless crys- 
tals, of a bitter taste, and the latter, yellow, brilliant prisms, 
»f a very bitter taste. The picrates explode when heated. 

Manv other compounds are derived from indigo. Sulphu- 



306 Organic Clwmisiry. 

ric acid dissolves indigo with the formation of two acids. 
The sulphindigotic acid is the most important, because it is 
the substance used for coloring Saxon blue. 

Red Dyes. The most common substances for red dyes, are 
cochineal, lac, archil, madder, Brazil-wood, and logwood. 

Cochineal is obtained from an insect, which feeds upon 
the leaves of several species of the cactus, and derives its col- 
oring matter from its food. 

It is very soluble in water, and is fixed on cloth, by means 
of alumina or oxide of tin. Its natural color is crimson, 
but when bitartrate of potassa is added to the solution, it 
yields a rich scarlet dye. The beautiful pigment called 
carmine, is a lake made of cochineal and alumina or oxide 
of tin. 

Archil is obtained from certain lichens, which grow in the 
Canary Islands. From the Roccella Tinctoria or archil 
plant, several compounds have been obtained. 

Erythrilin, (C 32 H 16 6 ,) is a white powder. Erythrin, 
(C 20 H 13 O 9 ) which is formed into brilliant snow-white scales, 
becoming brown on exposure. Amarythrin, (C 22 H 13 14 ,) and 
several other bodies are also found. 

The archil of commerce is obtained mostly from the Par- 
melia, but the principle most active in any of the lichens 
is Orcein, which is of a fine red color ; with ammonia or 
potash it gives a most splendid purple color, and various 
lakes are formed from its combinations with alkalies and 
metallic oxides. 

Litmus is prepared from archil, and from this substance, 
which is blue, red coloring matters are obtained. 

Madder is the root of the rubia tinciorum, and contains a 
peculiar coloring principle. 

Alizarin. (C 37 H 14 10 .) It exists as a red powder, which 
may be made to form long slender needles, soluble in boiling 
water. There are several coloring matters obtained from 



Nutritive Substances. 397 

madder, as Madder-purple, Madder-red, Madder-orange, 
Madder-yellow, Madder-brown. 

The most beautiful reds and purples are obtained from this 
substance, as well as those most durable — the Turkey-reds 
and lakes. 

Yellow Dyes. The principal, are quercitron bark, tumeric, 
saffron, and fustic. Several distinct principles are found in 
these substances, which are the coloring matters in yellow 
dyes. 

Black Dyes are prepared from the same ingredients as 
writing-ink. Logwood contains a crystalline reddish sub- 
stance, called Hematoxylin, which is the coloring principle of 
black and blue-black c 

Section VII. Nutritive Substances. 

In addition to the substances already described, such as 
starch, sugar, lignin, &c, there exists in vegetables a dis- 
tinct class of bodies, containing nitrogen, and small quantities 
of sulphur and phosphorus. They are the substances which 
nourish animals, and form, with but slight change of prop- 
erties, the muscles of animals. They are also found in the 
blood and some other fluids of the animal body. These sub- 
stances have a strong tendency to putrefaction when exposed 
to the air. They are, Fibrine, Albumen, Legumine, Caseine, 
Proteinc, and Gelatine. 

Fibrine. Vegetable fibrine may be obtained from wheat 
flour, by separating the starch ; the tenacious substance which 
remains is called gluten, (see p. 344) but it is mostly vegetable 
fibrine. 

Animal fibrine is probably the same substance, somewhat 
changed by the animal organs. It is the basis of muscle, 
and exists in the blood, from which it may be obtained by 
stirring freshly drawn blood with a stick ; the fibrine ad- 
heres, and when washed, is a white substance, becoming 
somewhat horny on drying. When subjected to the action 



^ 8 Organic Chemistry* 

of nitric acid, it throws off a large quantity of nitrogen , 
with acetic acid, it forms a jelly. 

Albumen. Vegetable albumen exists in the juices of 
plants, and in their seeds. 

Animal albumen is very similar, if not identical, with it; 
and is found, in a solid state, in the skin, glands, and vessels 
of animals • and in a liquid state in the serum of the blood, 
the fluid of dropsy, and the white of eggs. When liquid, it 
is coagulated by heat, as in the boiling of an egg, or by 
alcohol and the stronger acids. Corrosive sublimate is a 
very delicate test, producing a milkiness in water which con- 
tains -Ufa- part of albumen. 

Legumine, Vegetable Caseine, exists in the seeds of beans 
and peas, from which it is obtained by the action of acetic 
acid. It resembles the curd of milk. 

AnimalCaseine is similar to the above, and is the substance 
known as milk curd. It is obtained from milk, in which it is 
held in solution by an alkali, by adding dilute acids. When 
milk sours and coagulates, lactic acid is formed from the su- 
gar it contains, aided by caseine in a state of decomposition. 
Rennet, a substance formed by soaking the lining membrane 
of a calf's stomach in water, acts like caseine, and facilitates 
the coagulation of the milk, as in the manufacture of cheese. 
All these substances are identical in composition. They are 
formed by the vegetable, taken into the animal organism, and 
assimilated with but slight change of properties. 

Proteins <C"H 8 °N*CF) is obtained from either of the above 
substances by heating them in a dilute solution of potash, 
and adding acetic acid, a white solid is precipitated, which 
was discovered by Mulder, and named proteine. It differs 
from the substances from which it is derived by not contain, 
ing sulphate of lime and salts of soda. It appears to be 
closely allied to albumen and fibrine, and nearly identical 
in composition. 

Gelatine, C»H"N*0\ This substance is abundant fe ' 



LomjJiex Animal Substances. 399 

the solid parts of animals, in the skin, cartilages, membranes, 
and bones. It is very soluble in boiling water, and forms a 
bulky jelly on cooling. One part in 100 of hot water will 
render the whole solid on cooling. The jelly is a hydrate of 
gelatine ; and, if the water be expelled by gentle heat, it 
may be preserved for any length of timec This is known as 
glue, which is prepared from the ears, skins, and hoofs of 
animals. 

Isinglass is a pure variety obtained from the sounds offish. 
It is the gelatine which forms leather by uniting with tannic 
acid, and for this purpose the skins of animals are steeped in 
an infusion of oak or hemlock bark, and the gelatine forms 
an insoluble compound with the tannic acid. 

Glycocoll* or Gelatine Sugar (C 4 H 4 N0 3 .HO) is formed by 
the action of sulphuric acid on gelatine, or isinglass ; also by 
boiling hippuric acid with sulphuric or any of the stronger 
acids, benzoic acid and a salt of glycocoll are formed. This 
substance is then obtained by decomposing the salt. 

Properties. A crystalline solid ; taste sweet ; neutral to 
test paper ; soluble in water ; nearly insoluble in alcohol ; 
performs the part both of a base and of an acid, and forms a 
large number of compounds, by uniting with acids and bases 

Section VIII. Complex Animal Substances. 

Blood. Blood consists of a clear liquid, through which 
are diffused red globular particles. The liquid portion con- 
sists of water holding in solution fibrine, albumen, saline and 
oily matters. When set at rest it coagulates, forming a jelly. 
The red, or orange-red globules in the higher animals, are 
spherical and ellipsoidal, marked with a colorless spot in 
the centre. These globules are compound, consisting of a 
sack, which is allied to fibrine in composition, and a coloring 
, matter which is called 

Hematosiiiov Hematine. C 44 H a2 N 3 8 Fe. The iron is not, 

* A very able paper on Glycocoll and its compounds, may be found in 
Billiman's Journal, Noa. 9, 10, and 12, (1847,) by Prof. E. N> Hosford, 



400 Organic Chemistry. 

however, essential lo its constitution, as it may be separated 
from it. It has been supposed that the scarlet color of arte- 
rial blood was due to peroxide of iron ; but hematine is not 
altered in color by this substance, nor is it changed by the 
action of oxygen. 

It is a brownish-red solid, and when in solution its color :j 
similar to venous blood. The color of this substance is 
changed to that of arterial blood by the action of alkalies, so 
that the change of color from red to scarlet, by the action of 
the oxygen of the air, is not satisfactorily accounted for. 
Mulder has suggested the hypothesis that the action of the 
oxygen in the lungs upon the fibrine surrounding the blood 
globules forms a layer of proteine, which is white, and 
gives the scarlet tint. During the circulation, this matter is 
taken up, and the globules appear dark again in venous blood. 

Liebig ascribes the change of color which the venous 
blood undergoes by the action of oxygen, to the peroxidation 
of the iron in the blood. Thus venous blood contains car- 
bonate of the protoxide of iron, which gives it the dark 
color ; but when it meets a stream of oxygen gas in the 
lungs, the oxygen unites with the protoxide of iron ; con- 
verting it into the linoxide, which gives the arterial blood the 
scarlet color ; while the carbonic acid is expelled or cast out 
in the atmosphere. During the circulation, the oxygen com- 
bines with the worn-out tissues, forming carbonic acid, which 
appears in venous blood, combined with protoxide of iron : 
this protocarbonate is again decomposed by oxygen. 

When blood is set at rest, it does not separate into the two 
parts above mentioned, but into a red coagulum, called the 
clot and the serum. The latter is a yellowish liquid. The 
saline substances contained in the blood are carbonates, 
phosphates, and sulphates of potassa and soda. It contains 
also chloride of sodium, {common salt,) chloride of potassium, 
and, as we have seen, oxide of iron. More than three-quar- 
ters of the blood is water : coloring matter .125, and albumei? 



I 



Animal Heat Theories. 401 

.067, though the proportions vary somewhat even in the same 
person at different times. 

The following table, by M. Le Canu, represents the com- 
position of the blood as derived from two careful analyses : — 

Water, 780.145 785.590 

Fibrin 2.100 3.565 

Coloring matter, 133.000 119.626 

Albumen, 65.090 69.415 

Crystalline fatty matter, 2.43 4.300 

Oily matter, 1.310 2.270 

Extractive matter, soluble in water and alcohol, . .790 1.920 

Albumen combined with soda, .... 1.265 2.010 

Chloride of sodium, . . . ~) 

" of potassium, 
Carbonates 1 )> • . 8.370 7.304 

Phosphates > of soda and potassa, 
Sulphates ) J 

Carbonates of lime and magnesia, 

Phosphates of lime, magnesia, and iron, V . 2.100 1.414 

Peroxide of iron, ) 
Loss, 2.400 2.586 

1000.000 1000.000 
Animal Heat. There is a striking analogy between the 
process of combustion and respiration. In both cases, oxygen 
is consumed, and carbonic acid produced. This fact led 
Dr. Black to infer that the heat generated in the animal sys- 
tem was derived from the. change which takes place in the 
lungs. That the development of animal heat is dependent 
upon respiration, is a matter of easy demonstration ; but how 
the effect takes place, has not been satisfactorily explained. 
In those animals which consume a small quantity of oxygen, 
the temperature of their bodies varies with the surrounding 
medium, and are called cold-blooded ; but in those that con- 
sume a larger quantity of oxygen, the temperature is nearly 
uniform, whatever be the temperature of the medium. They 
a**e hence called warm-blooded. The temperature of the 
same animal varies often, according as the respiration is 
sluggish or rapid. 

To account for animal heat, Dr. Crawford proposed the 
iirst consistent theory, which is founded on the supposition 
that the blood, when purified by the oxygen of the air, haa 



402 Organic Chemistry. 

its capacity increased for caloric ; and hence the heat pro. 
duced in the lungs by the consumption of the oxygen, enters 
into an insensible state in the arterial blood. As this blood 
circulates through the system and enters the veins, it loses its 
capacity, and gives out its caloric. But Dr. Davy denies that 
there is any difference between the capacity of venous and 
arterial blood. If, however, we suppose that the oxygen doea 
not combine with the carbon in the lungs, but in the course 
of circulation, there would be heat developed in all parts of 
the system ; and this view would account for ihe facts, irre- 
spective of the different capacities of the two kinds of blood. 

MM. Dumas and Boussingault have proposed a theory 
which is received. with much favor by chemists. They sup- 
pose that the oxygen of the air on entering the blood, con- 
verts its soluble matters into lactic acid, which unites with 
soda, forming lactate of soda. The oxygen converts the lac- 
tate into carbonate of soda. A new portion of lactic acid de- 
composes this salt and liberates the carbonic acid, which 
appears in the venous blood. In this case there is a true 
combustion — the combination of oxygen with carbon. But 
whatever view be adopted of the action of oxygen in pro- 
ducing animal heat, there can be no doubt but that the union 
of the oxygen of the air with the worn-out tissues of the body, 
and with substances taken as food, which are rich in hydro- 
gen, as oils, fats, &c, are sufficient to account for the 
heat which is generated in the animal system. The action 
of oxygen is to burn up the system, 1st, by uniting with those 
particles which have served their purpose in the animal 
economy, and must be removed, and their places supplied 
with others endowed with a higher degree of vitality, and 
2dly, by combining with that portion of the food which is in* 
tended for respiration, and not for nutrition. 

Water and carbonic acid are the products of this combus- 
tion, and are not only expelled through the lungs, but ex* 
haled from all parts of the body. 



Gastric Juice. — Bile. 403 

Saliva. This liquid contains only seven parts of solid 
matter in a thousand. It contains chloride of potassium, 
sulphate, phosphate, acetate and carbonate of potassa, with 
some other salts, and an animal substance called fly aline. 
It forms a soft, pulpy mass with the food in mastication, pre- 
paring it for more easy digestion. 

Gastric Juice. This fluid taken from an empty stomach 
has a saline taste, and is neutral. But when any substance 
enters the stomach, acid is secreted. Both hydrochloric and 
acetic acids are formed. All nutritious substances are dis- 
solved by this juice, and converted into a pulpy mass called 
chyle. It does not act on living substances, or the stomach 
itself would be dissolved, as sometimes is the fact after death. 
Its solvent power is due to the acids, which are greatly aided 
by the temperature of the stomach. By taking magnesia, the 
acids are neutralized, and the digestive power suspended for 
the time. The gastric juice consists mostly of pepsin. 

Bile. The bile is a yellow or greenish, nauseous liquid., 
of which •£ are water, and the remainder a peculiar bitter 
principle called bilin, with resin, and several salts. The bile 
stimulates the intestinal canal, and assists in converting the 
chyme into chyle. 

The bilin is translucent, colorless, and inodorous, with a bit- 
ter and somewhat sweetish taste. In the resinous portion, a 
white earthy substance has been obtained, called dyslysin. 

Taurin (C 4 H 7 N0 10 ) is another substance, which has been 
derived from the bile. It is a crystalline solid, neutral and 
of a weak taste. Several acids have also been obtained from 
Dile : cholic acid, which crystallizes in fine needles, and has 
a sharp sweet taste \fellinic acid, which is a white, inodorous, 
and bitter solid, fusing at 212° ; cholinic acid, also, a whitish 
substance, insoluble in water, but soluble in alcohol ; bileverdin, 
a greenish-brown mass without taste, soluble in alkalies, and 

Cholesterin (C 37 H 32 0.) which is also a constituent of the 
brain and nerves. It is a crystalline substance, and is found 



404 Organic Chemistry. 

in the greatest abundance in gall stones, which are solid con- 
cretions in the gall bladder. 

Chyle. This is a white fluid resembling milk. It contains 
about 90 per cent, of water ; of the other constituents, albu- 
men is most abundant. 

Milk. This liquid is well known to consist of cream, 
curd, and whey. 100 parts of cream, of specific gravity 
1.0244, contain only 4.5 parts of butter ; of the remainder, 
92 are whey, and 3.5 curd. The coagulation in sour milk is 
produced by the generation of lactic acid, which, in common 
with acids generally, separates the curd from the whey. 
The same effect is caused by rennet prepared from a calfs 
stomach, which is impregnated with the gastric juice, and 
therefore contains acid. Milk is of course curdled when 
taken into the stomach. 

Lymph is a peculiar, limpid, transparent liquid, which 
moistens the cellular membrane, and collects, abundantly in 
some dropsical affections. It consists chiefly of water, with 
hydrochlorate of soda and albumen. 

The humors of the eye contain more than 80 per cent, of 
water ; the other ingredients are albumen, muriate and ace- 
tate of soda, pure soda, and an animal matter like curd, 
which gives it a milky appearance. 

The tears contain pure soda, chloride of sodium, and phos- 
phate of soda, with water, and an animal matter analogous to 
albumen. 

Mucus is a fluid secreted by the mucous surfaces, as the 
nose. 

Pus is a liquid matter secreted by an inflamed and ulce- 
rated surface. Its characteristic ingredient resembles al- 
bumen. 

Sweat is the vapor which constantly passes off from the 
skin, and consists mostly of water, mixed with a little muriate 
of soda, and free acetic acid, and perhaps formic acid. 

Urine differs from most animal fluids in serving no ulterioi 



Urinary Calculi. 405 

purpose in the animal economy. It is an excretion consisting 
of substances which would prove injurious to life and health. 
The urine is separated by the kidneys from the blood, and 
consists of a great variety of substances, such as water and 
urea, which are the principal, uric acid, lactic acid, lactate 
of ammonia, mucus, sulphates of potassa and of soda, phos- 
phates of soda and of ammonia, muriates of soda and of am- 
monia, earthy matters with a trace of fluate of lime, and sili- 
ceous earth. 

Urinary Calculi are solid concretions found in the urinary 
organs. The following are some of the varieties: — 

Xanthic Oxide (C 6 N 2 H 2 2 ) is among the most rare of these 
calculi, it is of a light-brown color, and may be known by 
its solubility in caustic potassa, from which it is precipitated 
by carbonic acid. 

Cystic Oxide (C 6 NH 6 4 S 2 ) is also rare ; color yellowish- 
white and brilliant waxy-lustre. It may be known by being 
soluble in caustic potassa, from which acetic acid separates 
it in the form of hexagonal plates. 

Mulberry Calculus, (Oxalate of Lime,) Bone Earth Cal- 
culus, (Phosphate of Lime,) and Ammoniaco-Magnesian Phos- 
phate Calculus, are more common, and may be known by 
very simple tests. Calculi are more commonly formed of uric 
acid and nitrate of ammonia. 

Eggs. The shell of an egg is about tV? the white -fa, and 
the yolk ■?$■ of the whole. The shell consists chiefly of car- 
bonate of lime ; and the white, of albumen, with a little sul- 
phur. The yolk contains phosphorus, which supplies phos- 
phoric acid for forming the bones of the chicken. 

Bones. Bones contain about •£ of animal matter, ■£ of phos- 
phate of lime, -jV of carbonate of lime, with a little fluoride 
of calcium, and some other salts. Teeth have the same com- 
position, but the enamel contains 78 per cent, of phosphate 
of lime. The shells of crustaceous animals, as lobsters and 
crahs, consist of carbonate and phosphate of lime, with ani- 



406 Organic Chemistry. 

mal matter; but the shells of molluscous animals, or true 
shells, as of the oyster, snail, etc., consist almost entirely oi 
carbonate of lime and animal matter. 

Horn differs from bone in containing only a trace of earth. 
The composition of the nailsj hoofs, and cuticle of animals is 
similar to horn. 

Tendons are composed almost wholly of gelatin. 

The true skin has nearly the same composition. Mem- 
branes and ligaments contain in addition some substance 
which is insoluble in water, and is similar to coagulated al- 
bumen. 

Hair contains* a peculiar animal substance, insoluble in 
water at 212°, but soluble in a solution of potassa. It also 
contains an oil, which gives the peculiar color of the hair, 
sulphur, upon which the nitrate of oxide of silver acts in stain- 
ing it, together with silica, iron, manganese, and carbonate 
and phosphate ol lime. 

Wool and feathers are similar in composition to hair. 

Silk is covered with a peculiar varnish, which amounts to 
about 23 per cent. 

Muscle. The lean flesh of animals consists essentially of 
fibrin, with numerous other ingredients, such as albumen, 
gelatin, a peculiar extractive matter called osmazome, fat, 
and salts. 

Brain and Nerves. The brain consists of 7 parts of albu- 
men, 5 parts of fatty matter, and 80 parts of water. The 
fatty portions contain two peculiar acids. 

Cereoric Acid, which appears in white crystalline grains, 
soluble in boiling alcohol, and swells up like starch in con 
tact with boiling water, without being soluble. It is com. 
bustible, fusing at a high temperature. 

Oleophosphoric Acid is separated from the preceding by thf 
action of ether. It is a viscid substance, forming soaps with 
alkalies. Cholesterin, olein and margarine, are also found 



Growth and Nourishment of Plants and Animals. 407 

in the brain, with lime, phosphorus and soda. The nerves 
have a similar constitution. 



Section IX. Growth and Nourishment of Plants and An- 
imals. 

Germination refers to the process by which a new plant 
originates from the seed. The seed consists of two parts. 
The germ, which is endowed with the vital principle, and the 
cotyledans, or seed-lobes, which furnish nourishment to the 
plant before it can derive it from the earth. The germ is 
composed of the radicle, or that part which descends into the 
ground, and forms the root, and the plumula, which rises into 
the air, and forms the stem of the plant. 

The three conditions necessary to the germination of the 
plant, are moisture, a certain temperature, and oxygen gas. 
Dry seeds will not germinate, or, if moist, germination will 
not take place at 32°, nor at the temperature of boiling water, 
which deprives the germ of its vitality. The most favorable 
temperature is from 60° to 80°, varying with the nature of 
the plant. Air is also necessary to germination ; for if seeds 
are buried deep, excluded from the air, they will never pass 
through this process. 

In the malting of barley, the process of germination may 
be accurately studied. The malting is done .by exposing the 
grain to moisture, warmth, and air, until it begins to germi- 
nate, and then drying it in a kiln, where the temperature 
ranges from 100° to 160°, or more. The chemical changes 
which take place in this .process, are the following : The 
hordein, an insoluble substance, is converted into starch, 
gum, and sugar, which are soluble and very nutritive sub- 
stances, easily absorbed by the radicle of the plant; at the 
same time, oxygen gas is consumed, and carbonic acid gas 
is given off. 

Growth of Plants. There are. many points of resemblance 



408 Organic Chemistry. 

between the growth of plants and of animals ; and also many 
points in which they differ. The plant absorbs carbonic 
acid, and yields oxygen, but the animal absorbs oxygen, and 
yields carbonic acid. The absorption of the acid by the 
plant is the natural mode of obtaining food. The oxygen it 
gives out is an excretion resulting from the assimilation of 
the carbon, but the absorption of oxygen by animals is for a 
very different purpose. It is to purify the system, by burn- 
ing up particles which can no longer retain their vitality, 
and to keep the animal warm. 

The growth of plants proceeds by continued or annual ad- 
ditions, which ever remain a portion of the trunk, but the 
growth of animals proceeds in a very different manner ; the 
matter of their bodies is continually changing. 

Plants are nourished mostly by inorganic substances, while 
animals must have organized structures for their support. 

Food of Plants. The food of plants has been a subject 
of much controversy. The elementary substances, oxygen, 
carbon, hydrogen, nitrogen, and a few metallic salts, are the 
only constituents of plants and of animals, and it would seem 
to be an easy matter to point out the source, and the mode 
in which they are assimilated or combined to form vegetable 
or animal bodies. But there is still some difference of opin- 
ion on the subject. 

Source of Carbon. Carbon is the most abundant constitu- 
ent of plants. 

Whence do plants obtain it ? 

There can be no doubt but that a large quantity of this 
substance is derived from the carbonic acid of the atmos- 
phere ; for it is a well-settled doctrine among vegetable phys- 
iologists, that the leaves and green parts of plants absorb car- 
bonic acid during the day, and by the aid of solar light, de- 
compose it — assimilating the carbon, and yielding back the 
oxygen to the air. Carbonic acid is also generated by the 
decomposition of vegetable matter in the soil, and absorbed by 



Source of the Organic Constituents of Plants. 409 

the water with which it enters the roots of plants, ascendj 
to the leaves, where it is decomposed by the action of light. 

So large a portion of the carbon of plants is derived from 
the carbonic acid of the atmosphere, that a distinguished 
chemist (Liebeg) has attempted to prove that carbonic acid 
is the only source of carbon. It is admitted by all chemists 
and vegetable physiologists that carbonic acid is the principal 
source, but other substances rich in carbon, such as the con- 
stituents of vegetable mould, which have been described un- 
der the names of liumus, liumic acid, geine, ulmin, mav also 
furnish to plants a portion of their carbon. 

It will be readily seen that previous to the formation of 
coal beds, the quantity of carbonic acid in the atmosphere 
must have been much greater than at present — for we find 
that coal originated from living vegetables — and these veg- 
etables obtained their carbon mostly from the atmosphere. 
Ihe quantity of carbonic acid in the atmosphere is easily es- 
timated, and the quantity of coal or carbon which it is ca- 
pable of yielding, in the form of wood, &c. The quantity 
of coal stored up in rocks can also be estimated with some 
degree of accuracy ; and from those estimates, it is supposed 
that the atmosphere once contained at least five times as 
much carbonic acid at it does at the present time ; and, hence, 
we may account for the absence of air-breathing animals in 
early geological times. Air-breathing animals make their 
appearance on the earth's surface immediately after the coal 
beds were deposited, and not before. If our atmosphere 
contained five times its present quantity of carbonic acid > 
it would prove injurious to animal life, perhaps, wholly de- 
structive of it. 

Source of Oxygen and Hydrogen. There can be but little 
doubt but that water yields both oxygen and hydrogen to 
plants, in fact, woody fibre contains oxygen and hydregen in 
the same proportion as in water. A certain quantity of car- 
bon united to the elements of water would form woody fibre ; 

18 



410 Organic Chemistry. 

but in some compounds hydrogen, and in others, oxygen, is 
in excess. 

Hydrogen may be 'iSerived from ammonia, (NH 3 ,) and both 
oxygen and hydrogen from vegetable mould. 

Source of Nitrogen. Nitrogen is derived from ammonia, 
which exists in the atmosphere and in all fermenting manures. 
Nitrogen may also be obtained from nitre and from vegetable 
mould. 

The unorganized portions are all derived from the earth, 
absorbed through the roots, and with water, introduced 
into the circulation. Out of these simple elemental sub- 
stances, vegetables manufacture all their peculiar principles. 
The nutritious matters pass first to the leaves, which seem to 
be the great organs of digestion and respiration ; from the 
leaves the matter descends between the bark and wood in 
exogens, and passing through several transformations, de- 
posits a layer of new wood, which forms a ring of annual 
growth. The conditions of the growth of plants, and the 
means by which their products may be increased, belong to 
the science of Agricultural Chemistry. To the numerous 
works on that subject, the student is referred for full infor- 
mation. 

Nourishment of Animals. Animals originate in a different 
manner from plants — the one from a seed, the other from an 
egg ; and yet the composition of animal bodies is identical 
with that of vegetables ; for, although animals are endowed 
with a higher degree of vitality than vegetables, they have 
not the power of forming any portion of an animal tissue, or 
any other animal substance, out of inorganic matter — they 
merely assimilate the substances which vegetables form. 
There is nothing in animal bodies which is not found in veg- 
etables. The process of growth, however, is much more 
complicated, the nutritive matters taken from vegetables are 
assimilated and made a part of animal bodies, after having 



Nourishment of Animals. 411 

passed through the process of digestion and purification by 
the action of oxygen. 

The crude material passes through a process of purifica- 
tion, by which the nutritious matters are appropriated to the 
sustenance and service of the various organs. All substances, 
which are strictly nutritious, contain nitrogen ; hence, oils, 
fats, sugars, &c, are not strictly nutritious, and will not sup- 
port life for a long time. All the animal tissues and organs 
contain nitrogen. That portion of their food which does not 
contain nitrogen, is used for the purposes o£ respiration. One 
object of respiration is to produce heat. It is easy to see, 
why it is that those animals which inhabit cold climates re- 
quire a larger quantity of food for respiration, than those 
that live near the equator ; why more of such food is re- 
quired in winter than in summer ? why those animals that 
pass into a torpid state during the winter, lay up large quan- 
tities of fat in the autumn, to be consumed in keeping their 
bodies at a temperature at which life can be maintained dur- 
ing the winter. An animal, during its torpid state, has a 
very sluggish respiration — yet sufficient oxygen enters the 
lungs to combine with the fat, to consume it, so that in the 
spring, they come out of their sleep, very much emaciated. 
In fact, an animal is like a furnace in one respect, it uses up 
fuel in the form of non-azotized food, and the worn-out tis- 
sues of the body, converting them into carbonic acid, water, 
and ammonia. 

By the process of respiration, the oxygen of the atmos- 
phere is consumed, and its place supplied by an equivalent 
volume of carbonic acid. 

The process of respiration is not the only source of car- 
bonic acid ; the process of combustion, also generates carbonic 
acid in large quantities ; the decomposition of vegetable mat- 
ter is still another source — to this may be added a large 
quantity thrown into the atmosphere from changes going on 
amon£ tbe rocks. 



412 Analytical Chemistry. 

Why is not the atmosphere wholly converted into carbonia 
acid ? Simply because this acid is absorbed by vegetables, 
its carbon assimilated, and its oxygen sent back*to the at- 
mosphere, as pure as at first, again to enter the animal 
organs, and to become the means of supplying to plants the 
carbon they need for their growth. This most intimate and 
Deautiful relation of the vegetable and animal kingdoms, fur. 
nishes one, out of numberless illustrations of the Divino 
wisdom, which cannot fail to excite the admiration of ever) 
observer. 



CHAPTER VI. 

ANALYTICAL CHEMISTRY. 

It is the object of analytical chemistry to point out the 
method of separating compound bodies into their simple 
elements. As the subject is extensive, a few things only 
will be inserted here, in order to give the student an idea of 
the nature of the process. 

Sect. 1. Analysis op Mixed Gases. 

1. Gaseous Mixtures containing Oxygen. p^ 10 2. 
The best process by which oxygen gas may 
be withdrawn from gaseous mixtures, is by 
means of hydrogen gas. In case of the air, 
a given portion is taken, and rather more 
hydrogen added than is sufficient to com- 
bine with the oxygen. The mixture is then 
introduced into a strong glass tube, or eudi- 
ometer, (Fig. 102,) over water or mercury, 
and exploded by the electric spark. The 
total diminution in volume, divided by three, 
will give the quantity of oxygen present. 
Instead of exploding the gases, they may be 
made to combine slowly, by introducing into the mixture 
platinum spoag*. 





ST"* 




6 


\ 


b 




-a 






„--.. 





Analysis of Minerals. 413 

2. Gaseous Mixtures containing Nitrogen. As the air 
contains only oxygen and nitrogen, when other substances 
are withdrawn, if its oxygen is determined, the quantity of 
its nitrogen may be easily known. The only mode of ascer- 
taining the quantity of nitrogen in any mixture, is to with- 
draw the other gases from it. 

3. Gaseous Mixtures containing Carbonic Acid. When 
carbonic is the only acid gas present, as is the case with air 
and organic compounds, the process consists merely in ab- 
sorbing this gas by lime water, or a solution of caustic potassa. 

4. Gaseous Mixtures containing Hydrogen and other In- 
flammable Bodies. The quantity of hydrogen, when mixed 
with nitrogen, oxygen, or atmospheric air, is ascertained by 
adding a portion of oxygen, and exploding the mixture. The 
quantity of other inflammable bodies, such as carbonic oxide, 
fight carbureted hydrogen, or olefiant gas mixed with nitro- 
gen, is determined by adding a sufficient quantity of oxygen, 
and detonating the mixture. The diminution of volume in- 
dicates the quantity of hydrogen contained in the mixture, 
and by withdrawing the carbonic acid, the quantity of car- 
bon may be known. 

Sect. 2. Analysis of Minerals. 

In order to analyze any mineral compound, the first object 
is to bring the body into a state of solution. This is effected, 
generally, by water or acids; but in cases where the sub- 
stance is not dissolved by these, it is made into a paste, with 
three or four times its weight of fused borax, potassa, soda, 
baryta, or their carbonates, and subjected to a strong heat, 
in a platinum or silver crucible. By this means, the alkali 
combines with one or more of the constituents of the min- 
eral and then it is in a state to be acted upon by acids. 

I. Analysis of Minerals soluble in Acids with Effervescence. 

Reduce the mineral to a fine powder, and boil it for two hours in 
the acid which holds it in solution, diluted with five or six times its 
bulk of water. This solution may contain lime, baryta, magnesia, 
•trontia, alumina, and oxides of metals. 

1. Add to a small portion of the liquor, diluted with 20 parts of water, 



414 



Analytical Chemistry. 



sulphate of soda, and if a precipitate appear, baryta, or stroiitia, or 
both, are present. Nitric acid, diluted with an equal weight of water, 
will dissolve the strontia, if present, in the separated precipitate, but 
will not act upon the baryta. 

2. Add to a portion of the liquid, ferrocyanate of potassa, and if 
metallic oxides are present, a precipitate will be thrown down, the 
color of which will probably show the kind of metal. 

3. Carbonate of potassa will precipitate the lime, magnesia, and 
alumina, from which the alumina may be dissolved by a solution of 
potassa, and precipitated again by dilute hydrochloric acid. 

Having precipitated the alumina, dilute hydrochloric acid wnl re- 
dissolve what remains, from which oxalate of ammonia will precipitate 
the lime. 

Add to the remaining liquid, in successive portions, carbonate of 
ammonia and phosphate of soda, and magnesia, if present, will be pre- 
cipitated, 

II. Analysis of Minerals which are insoluble in Acids. 

Heat a mixture of 1 part of the mineral to 3 of fused borax, for three 
hours, in a platinum crucible ; dissolve the contents by digesting the 
whole in hydrochloric acid, for several hours ; add carbonate of am- 
monia, and the whole will be precipitated; filter and wash the precipi- 
tate, to separate the borax, and re-dissolve in hydrochloric acid. If any 
matter remain, it is silica. The solution may then be tested as in the 
former case. 

. III. Analysis of Minerals containing Carbonate of Lime, Silica, 
Oxide of Iron, and Magnesia. 

1. Reduce the mineral to a fine powder, and weigh out a given por- 
tion, as 1000 grs. ;. dry the powder just up to browning paper; the loss 
of weight is water. 

2. Having put the powder into a flask, 
to which a cork with a bent tube is at- 
tached, (Fig. 103,) pour upon it water, and 
then hydrochloric acid, quickly inserting 
the stopper, and placing the tube in a ves- 
sel of baryta water ; carbonic acid will 
escape through the tube into the solution 
of baryta, and form carbonate of baryta, 
which will be in fine powder. Filter and 
dry the residue ; the weight will give the 
quantity of carbonic acid, 22 parts of acid 
being combined with 78 of baryta. 

3. Dilute the liquor in the flask with 
water, throw it upon a filter, and wash: 
the insoluble matter is silica. 

4. The washings of the filter contain a solution of the oxide and lime 
Precipitate the oxide with excess of ammonia ; filter, wash, dry, and 
weigh ; from this the iron may be estimated, as the oxide will contain 
12 parts of ox}' gen, 9 of water, and 28 of iron. Oxalate of ammonia will 
precipitate the lime from the remaining liquor, which being filtered, 
wa?hed, and burned in a crucible, lime only will remain. The magnesia, 
which is still in solution, may be precipitated by carbonate of ammonia 
in excess, and by adding phosphate of soda; filter, dry, and weigh ; 100 
parts will contain 40 of pure magnesia. 

The Compounds of Silica, Alumina, and Iron, are decomposed by al« 



Fig. 112. 




Analysis of Mezaaic xjrts. 415 

kaline carbonates, at a red heat. For further processes, see Turner's 
Chemistry, or Rose's Analytical Chemistry. 

IV. Tests of Metallic Ores. 

1 . Ores of Antimony are first dissolved in nitrohydrochloric acid, which 
lakes up all the sulphur. The oxide of antimony is then precipitated 
oy simply adding water. 

2. Ores of Lead are dissolved in nitric acid, with the exception of 
the sulphur, which may be separated by a filter ; add to the solution 
carbonate of soda, and carbonate of lead will be thrown down. The 
silver, if present, will also be precipitated, and may be separated from 
the carbonate of lead by liquid ammonia, which holus it in solution. 

3. Ores of Mercury are mixed with iron-filings or lime, and exposed, 
in an iron retort, to a strong heat; when the mercury will distil over. 

4. Ores of Zinc may be boiled in nitric acid to dryness, and the pro- 
cess repeated. If iron is present, it will be peroxidated, and dilute 
nitric acid will dissolve out the zinc ; filter the solution, and add liquid 
ammonia in excess ; the lead, if present, will be precipitated, and the 
zinc will remain in solution. The oxide of zinc is obtained by boiling 
this solution to dryness. 

5. Ores of Tin. As these ores usually contain silica, they must be 
first treated like an earthy mineral not soluble in acids. The tin will 
be detected by forming a purple solution with the chloride of gold. 

6. Ores of Iron. The peroxide of iron is first rendered soluble by 
heating it for an hour with one eighth of its weight of powdered char- 
coal. The black oxide is soluble in dilute hydrochloric acid. If phos- 
phate of iron is present, it may be detected by adding to the hydrochloric 
solution 10 parts of water, (which has been boiled, to separate the air,) 
placing it in a bottle corked tight, and set aside for 6 or 8 days, when 
the phosphate of iron will be precipitated. The filtered solution may 
contain oxides of iron, manganese, and zinc, all of which are thrown 
down by carbonate of soda. The oxide of zinc may then be separated 
.y ammonia, and the oxide of manganese by acetic acid. The oxide 
of" iron will then remain, and, after being ignited, will contain 72 per 

ent. of the pure metal. 

7. Ores of Copper are boiled dry with five times their weight of sul- 
pnuric acid. The sulphate of copper which is formed is dissolved by 
Water, and the metallic copper precipitated by a plate of clean iron. 

8. Ores of Silver are dissolved by nitric aeid. Immerse in the solu- 
tion a plate of polished copper, and the silver will be precipitated upon 
it, if no lead is present. Common salt will throw down the chloride 
of silver. 

9. Ores of Gold and Platinum are dissolved in nitrohydrochloric 
acid ; the solution is then evaporated until nitrous acid fumes cease to 
appear, and the odor of chlorine is perceptible ; the product is dissolved 
in water, and a solution of hydrochlorate of tin added, when a purple 
precipitate will be thrown down, if gold is present. If platinum is in 
the mixture, it may be precipitated by hydrochlorate of ammonia. 

When the solution contains gold with other metals, the sulphate of 
the protoxide of iron precipitates the gold with the palladium, mercury, 
and silver, if present. As silver is most frequently present, eommon 
salt should be added previous to the sulphate of iron, to precipitate it. 

Earthy Sulphates. The sulphate of lime is easily analyzed by boil- 
ing it for fifteen or twenty minutes in a solution of twice its weight of 
carbonate of soda. The carbonate of lime and sulDhate of soda are 



416 Analytical Chemistry. 

formed by double decomposition. The sulphate of soda is tnen de- 
composed by chloride of barium, and the carbonate of lime analyzed i» 
the usual way.* 

Sect. 3. Analysis of Mineral Waters. 

The purest water is obtained by distillation. Rain water 
or that from fresh fallen snow, is next in purity. 

Well and spring water contain some salts, which are de* 
rived from the soil through which the rain water passes . 
hence the purity of water will depend upon the nature of the 
soils. If it is filtered through primitive strata, such as gran- 
ite, it will contain few salts, but if through secondary soils, 
such as limestone and gypsum, it becomes impregnated with 
various other substances, and is mineralized. Lime renders 
it hard. 

The different kinds of mineral*^vater are acidulous, alka- 
line, chalybeate, sulphur eted, saline, and siliceous springs. 

1. In acidulous springs, of which those of Saratoga and 
Seltzer are examples, the acidity is due to the carbonic acid 
with which their waters are impregnated; they frequently 
contain protoxide of iron, carbonates of lime, magnesia, and 
other saline compounds. The carbonic acid is easily expelled 
by heat, and may be collected over mercury. 

2. Alkaline springs are very rare ; they generally contain 
a free or carbonated alkali. 

3. Chalybeate springs. These waters are characterized by 
styptic, inky taste, and by striking a black color with infu- 
sion of gall-nuts. The iron is either combined with hydro- 
chloric and sulphuric acids, or exists in the form of proto- 
carbonate, held in solution by free carbonic acid. On 
exposure to the air, the protoxide is oxidized, and the hy- 
drated peroxide subsides as an ochreous deposit, which is 
commonly found in the vicinity of chalybeate springs. — T. 

4. Saline springs owe their properties to saline compounds , 
such as sulphates and carbonates of lime, magnesia, and so- 
da, and the chlorides of calcium, magnesium, and sodium. 

In the analysis of saline springs, the first object is to ascer- 
tain the nature of the ingredients. Hydrochloric acid is 
detected by nitrate of oxide of silver, sulphuric acid by chlo- 
ride of barium; and if an alkaline carbonate be present, the 
precipitates will contain a carbonate of oxide of silver, or of 
baryta. Lime and magnesia may be detected, the former by 

* For other sulphates, see Turner, p. 241. 



Test Tubes. 



417 



Fig. 113. 



oxalate of ammonia, and the latter by phosphate of ammonia 
Potassa is known by the action of chloride of platinum. To 
detect soda, the water should be evaporated to dryness, the 
deliquescent salts removed by alcohol, and the matter insolu- 
ble in that menstruum taken up by a small quantity of water, 
and allowed to crystallize by spontaneous evaporation. The 
salt of soda may then be recognized by the rich yellow color 
which it communicates to flame. If the presence of hydri- 
odic acid be suspected, the solution is brought to dryness, the 
soluble parts dissolved in two or three drachms of a cold so- 
lution of starch, and strong sulphuric acid slowly added. — T 
Sulphurated springs are characterized by their odor, ana 
by the brown precipitate, which a salt of lead or silver occa- 
sions. This is owing to the hydrosulphuric acid gas which 
they contain. The quantity of gas is ascertained by boiling 
the water, which expels it. 

To detect Hydrosulphuric Acid. Take a flask, 
with a tube bent twice at right angles, one end 
of which dips into a solution of acetate of lead. 
(Fig. 104.) Introduce the water into the flask, 
and apply heat until it boils. The gas will be 
driven off, and decompose the acetate, forming a 
sulphuret of lead ; filter, dry, and weigh. 16.1 
parts will be sulphur, and 103.6 parts lead. T V 
part of the weight of the sulphur, added to its 
weight, will give the weight of the hydrosulphu- 
ric acid 

If the water, after being boiled, yields a black 
precipitate, with acetate of lead, acetic acid must be added, and the 
liquor boiled, and the gas passed through the acetate, as before. 

The mode of estimating the solid matter held in solution in mineral 
waters is simply to boil the whole to dryness, and weigh the residue. 
The different kinds of matter are then detected in the usual way for 
analyzing other solid bodies. 

Test Tubes. For 
the purpose of test- 
ing substances in 
solution, test tubes 
(Fig. 105) are very 
convenient. They 
AT; glass tubes, from 
3 to 12 inches in 
length, and from J 
to 1 inch in diame- 
ter, open at one end, 
whi.ethe closed end 
:'s so made that the 
liYruid may be heat- 




Fig. 114. 




418 



Analytical Chemistry. 



ed as in a retort. A small quantity of any solution may be 
examined in them with great facility, and they are especially 
convenient to form precipitates. These tubes may be placed 
upon a frame, as in the figure, and answer often the threefold 
purpose of retort, receiver, and test tube. 



Filtration. When a solution has been prepared for exam* 
ination, it ought to be perfectly clear. If it appears muddy, 
it must be subjected to filtration ; that is, it must be passed 
through a paper filter, by which means it is separated from 
solid matters, which make it appear opaque. As this opera- 
tion frequently occurs in chemical analysis, and in various 
manipulations, it is important to understand the mode of per- 
forming it. 

The filtering paper should contain no glazing or sizing, 
and should be folded in the following form : — 

1. Take a square piece of paper, and fold it like a sheet of 
paper, that is, so as to bring two corners together ; then fold 
it so as to bring four corners together ; cut off the corners, 
and by opening the folds it will have the form of an inverted 
cone, and may be placed in a funnel. 

Fig. 115. 

2. But for filtering rapidly, 
the filter may be folded in the 
following form : — Fold the pa- 
per in two, as before ; then (Fig. 
106) fold 10 upon 2, then 10 
c^cn 6, then 1 10 upon 1 8, 
then 2 upon 8, then 2 upon 6, 
2 upon 4, and 10 upon 4 : this will produce 
7 folds, all on one side of the paper. Make, 
now, folds between each of these, so as to 
raise ribs on the opposite side of the paper. 
Cut out the projecting corners, to give the 
whole a circularshape ; open it, and form it into 
a cup. (Fig 107.) 





Filtration 



419 



Fig. 117. 




The filter may then be placed 
in the funnel c, (Fig. 108,) and 
supported by a lamp-stand cr a 
wood-stand, made for the pur- 
pose ; or it may be placed in the 
top of a tall jar. The liquid to 
be filtered is then put into it, and 
a vessel placed beneath to con- 
tain the liquid as it slowly passes 
through the paper. By this pro- 
cess, the solid and liquid parts 
are separated, and either may 
be examined in their separate 
state.* 

if it is desired to estimate the quantity of solid matter, the 
filter must be weighed previous to placing it in the funnel ; 
and the solid matter, after being washed, by directing a fine 
stream of water upon it, until the water comes through taste- 
less, is dried and weighed : the difference of weight shows 
the quantity of solid matter. 

Supports of filters and vessels may be 
of iron wire, made into the form of a tri- 
angle. (Fig. 109.) Take three pieces of 
iron or copper wire, and twist the ends as 
in the figure, leaving a triangular aperture : 
this may be placed upon the tops of jars 
and other vessels, or upon the rings of the 
lamp-stand, to support crucibles, evapo- 
rating dishes, retorts, filters, &c. 



¥ig* 118. 




* For chemical manipulation, and blowpijjc analysis^ the student ia 
referred to Griffin's Chemical Recieations. 



APPENDIX 



Wollaston's Synoptic Scale of Cliemical Equivalents.* —• 
The scale consists of a movable slider, with a series of 
numbers upon it, from 10 to 320, on each side of which, and 
on the fixed part of the scale, are set down the names of va- 
rious chemical substances. 

The scale is founded on the constancy of composition in 
chemical compounds, the equivalent power of the quantities 
that enter into combinations, and the properties of a logo- 
metric scale of numbers. 

The numbers are so arranged, that at equal intervals they 
bear the same proportion to each other. The student wlfl 
easily observe and understand this, by measuring a few dis- 
tances upon the scale, with a pair of compasses, or even a 
piece of paper. If his paper extend from 10 to 20, it will 
also extend from 20 to 49, or from 55 to 110, or from 160 to 
320. Whatever number is at the upper edge of the paper 
will be double at the lower. If any other distance be taken, 
the same effect will be observed. If, for instance, the paper 
extends from 10 to 14, then any other two numbers found at 
its upper and lower edge will be in the same proportion as 
these two numbers 10 and 14. Thus, make the upper num- 
ber 100, and the lower number will be 140. 

Now, supposing that the paper were cut of such a width 
that, one of its edges being applied upon the scale to the num- 
ber representing the equivalent of one body, the other should 
coincide with the number of the equivalent of a second body ; 
then, upon moving the paper, wherever it was placed over the 
numbers, those at its upper and lower edges would still rep- 
resent the corresponding proportional quantities of the two 
bodies as accurately as at first, because the numbers at equa\ 

* The paper, by its author, describing the scale, is inserted in the 
Philosophical Transactions for 1814. 



Appendix. 421 

distances on the scale are proportional to each other. Thus, 
suppose the upper edge were made to coincide with 40 and 
the lower with 78, then the upper edge might be called sul- 
phuric acid, and the lower baryta ; and this width once as- 
certained, the paper, wherever applied upon the scale, would 
show at its lower edge the quantity of baryta necessary to 
combine with the quantity of sulphuric acid indicated by its 
upper edge. 

It is evidently of no consequence whether the paper be 
moved up and down over the scale, or the line of numbers 
be moved higher and lower, to bring its different parts to the 
edges of the paper. And supposing the piece of paper just 
described to be pasted upon the side of the scale, then, by 
moving the latter, any of the numbers might be made to coin- 
cide with the upper or lower edge at pleasure, and conse- 
quently the quantity of sulphuric acid necessary to combine 
with any quantity of baryta, and vice versa, ascertained by 
mere adjustment and inspection of the scale. Or if, instead 
of referring to the separate piece of paper, marks were to be 
made on the side of the scale at 40 and 78, and named sul- 
phuric acid and baryta, the same object would be attained, 
and the same method of inquiry rendered available. 

Other substances are to be put down upon the scale ex- 
actly in the same manner. Thus, the scale being adjusted 
until the number 40 coincides with the sulphuric acid already 
marked, then sulphate of baryta is to be written at 118, and 
thus its place is ascertained; nitrate of barvta at 132 ; soda 
at 32 ; sulphate of soda at 72 ; and a sirnnar process is to be 
adopted with every substance, the number of which has been 
ascertained by experiment. The instrument, which in this 
state merely represents the actual numbers supplied by exper- 
iment, will faithfully preserve the proportions thus set down, 
whatever the variation of the position of the slider may be. 
It is therefore competent to change all the numerical expres- 
sions to any degree required, the knowledge of one only being 
sufficient, first by adjustment, and then by inspection, to lead 
to the rest. 

A few illustrations of the powers and uses of this scale 
will be sufficient to make the student perfect master of its 
nature and applications. Suppose that, in analyzing a mineral 
water, the sulphates in a pint of it have been decomposed by 
the addition of muriate of baryta, and the resulting sulphate 
of baryta washed, dried, and weighed ; from its quantity may 



422 Appendix. 

oe deduced the exact quantity of sulphuric acid previously 
existing in the mineral water. Thus, if the sulphate of baryta 
amount to 48.4 grains, the slider is to be moved until that 
number is opposite to the sulphate ofbaryta> and then at sul- 
phuric acid will be found the quantity required, namely, 14.7 
grains. In the same manner the scale will give information 
of the quantity of any substance contained in a given weight of 
any of its compounds ; these having previously been deduced 
from experiment, and accurately set down on the table in the 
manner just explained. 

If it be desired to know how much of one substance must 
be used in an experiment to act upon the other, it is evident 
that the equivalent must be taken, and this may be learned 
from the scale. Suppose that a pound of sulphate of baryta 
has been mixed with charcoal, and well heated, to convert it 
into a sulphuret, and that by the addition of nitric acid it is 
to be converted into nitrate of baryta. The quantity of acid 
which will probably be required may be learned by bringing 
100 to sulphate of baryta, and then by looking for the num- 
ber opposite nitric acid ; it will be found to be 46. But this 
represents the quantity of dry acid ; casting the eye therefore 
lower down, upon liquid nitric acid of a specific gravity of 
1.50, it will be found that 61 lbs., or a little more, is the 
equivalent for 100 lbs., and consequently that 61 hundredth 
parts, or somewhat above y 6 ^ of a pound of such acid, will 
be sufficient ior the pound of sulphate of baryta operated 
with. 

If a certain weight of carbonate of baryta be required in 
that moist and finely-divided state in which it is obtained by 
precipitation, and in which it cannot be weighed, the accu- 
racy of the quantity may be insured by taking the equivalent 
of dry muriate, or nitrate of baryta, precipitating it by an ex- 
cess of carbonate of potassa, and then washing off the salts 
which remain in solution. Suppose 100 grains of the car- 
bonate were required ; by bringing that number to carbonate 
of baryta, it will be found that the quantity of dry muriate 
necessary will be 105.8 parts, and the quantity of nitrate 
133.4 ; and if the quantity of carbonate of potassa necessary 
for this purpose be also required, it will be found, opposite 
the name of that substance on the scale, to be a little less 
than 70 parts, so that 5 or 10 parts more will insure a satis- 
factory excess. 

The second paragraph of Wollaston's description of this 



Appendix. 423 

•scale may be transcribed, as a further illustration of the 
powers of the instrument. " If, for instance, the salt under 
examination be the common blue vitriol, or crystallized sul- 
phate of copper, the first obvious questions are — (1) How 
much sulphuric acid does it contain? (2) How much oxide 
of copper? (3) How much water ? He [the analytic chemist] 
may not be satisfied with these first steps in the analysis, but 
may desire to know further the quantities (4) of sulphur, (5) 
of copper, (6) of oxygen, (7) of hydrogen. As means of 
gaining this information, he naturally considers the quantity 
of various re-agents that may be employed for discovering the 
quantity of sulphuric acid, (8) how much baryta, (9) carbon- 
ate of baryta, or (10) nitrate of baryta, would be requisite 
for this purpose. (11) How much lead is to be used in the 
form of (12) nitrate of lead; and when the precipitate of 
(13) sulphate of baryta, or (14) sulphate of lead, are obtained, 
it will be necessary that he should also know the proportion 
which either of them contains of dry sulphuric acid. He 
may also endeavor to ascertain the same point by means of 
(15) the quantity of pure potassa, or (16) of carbonate of 
potassa, requisite for the precipitation of the copper. He 
might also use (17) zinc, or (18) iron, for the same purpose ; 
and he may wish to know the quantities of (19) sulphate of 
zinc, or (20) sulphate of iron, that will then remain in the 
solution." 

All these questions and points are answered by moving the 
slider until the number expressing the quantity operated with, 
coincides with sulphate of copper crystallized. 5, Water. 
Let it, for instance, be 100 ; this being brought opposite crys- 
tallized sulphate of copper, the information relative to all the 
above points, except the sixth and seventh, is supplied by 
mere inspection. The sixth may be supplied by substracting 
(5) the quantity of copper from (2) the quantity of oxide of 
copper, or by halving the quantity at 2 oxygen, or taking the 
third of that at 3 oxygen. The seventh relates to the quan- 
tity of hydrogen in the 5 water present in the salt; this quan- 
tity of hydrogen does not come within the line of numbers, 
but may easily be obtained by doubling the quantity of water, 
or doubling the quantity of the salt used, which will then 
bring 10 hydrogen into the scale, and the half of this is to be 
taken as the quantity in 5 water, or in 100 grains of the salt. 
Putting, therefore, 200 to sulphate of copper, 10 hydrogen, is 
indicated as 17 parts nearly, when of course the half of this, 



424 Appendix, 

or 8.5 parts, is tKe quantity in 100 grains of the crystallized 
salt of copper. 

Whenever it thus happens that the number known or the 
number sought for is out of the scale, then some convenient 
multiplier of the numoers may be used. The most conve- 
nient method is to use the tens or the hundreds as units, or, 
what is the same thing, to consider for the time that decimal 
points are inserted between the units and the tens, or between 
the tens and the hundreds of all the numbers on the scale. 
Thus, if it were required to ascertain how much magnesia and 
sulphuric acid were contained in a pound of crystallized sul- 
phate of magnesia, no 1 exists upon the scale, and of course 
no fractions or small parts of 1 ; but imagine decimal points 
between the tens and the hundreds, then 10 upon the scale 
becomes one tenth, 22 twenty-two hundredths, 100 one, 220 
two and two tenths, and so on. Bringing, therefore, 100 to 
crystallized sulphate of magnesia, it represents the 1 pound, 
and by inspection it will be found that it contains 16 hun> 
dredths of a pound of magnesia, and 32£ hundreds of a pound 
of sulphuric acid. 

As another illustration, suppose that the quantity of mag- 
nesia in 50 lbs. of crystallized Epsom salt were required; 
upon bringing 50 opposite the name of the salt, the quantity 
of magnesia will be found smaller than any quantity expressed 
upon the scale ; but all that is necessary to obtain the answer 
is, to double the quantity of the salt, and then to halve the 
quantity of magnesia indicated ; in which way it will be found 
that the 50 lbs. contain about 8 lbs. of the oxide. 

These Synoptic Scales are generally constructed of paper 
or wood. It is almost impossible that they should be accu- 
rate, because of the extension and contraction of the paper, 
and the facility w T ith which it yields to mechanical impressions, 
and maybe stretched when in a moistened state. These scales 
should never be considered as accurate when they first come 
from the instrument-maker. They may be examined by a 
pair of compasses or a piece of paper, to ascertain how nearly 
equal intervals on the scale of numbers accord with equal 
proportions between the numbers at the extremities of those 
intervals, and thus the degree of error in them, and the part 
where it exists to the greatest extent, may be observed ; but it 
will be useless to do so with the view of finding one so accu* 
rate as to dispense with calculation in exact analytical exper* 
iment. 



Appendix 425 

. % 

Those scales which are laid down directly upon wood, 
ihough not liable to the same sources of error as the paper 
scales, are still seldom, if ever, so accurate as to compete 
with calculation. — W. 

Cementing. 1. When vapors of watery liquors, and such 
others as are not corrosive, are to be confined, it is sufficient 
to surround the joining of the receiver to the retort with 
slips of wet bladder, or of linen, or paper, covered with flour 
paste, or mucilage of gum arabic. 

2. Soft cement is made of yellow wax melted with half its 
weight of turpentine and a little Venetian red to give it color. 
It can be easily moulded by the fingers, and sticks well to 
dry substances. 

3. For containing the vapors of acid, or highly-corrosive 
substances, fat lute is made use of. This is formed by beat- 
ing perfectly dry and finely-sifted tobacco-pipe clay, with 
painters' drying oil, in a mortar, to such a consistence that it 
may be moulded by the hand. To use it, it is rolled into 
cylinders of a convenient size, which are applied, by flatten- 
ing them, to the joinings of the vessels, which must be quite 
dry, as the least moisture prevents the lute from adhering 
The lute, when applied, is to be covered with slips of linen 
spread with the lime lute ; which slips are to be fastened 
with pack-thread. 

4. When penetrating and dissolving vapors are to be con- 
fined, the lute to be employed is of quick lime slacked in the 
air, and beaten into a liquid paste with white of eggs. This 
must be applied on strips of linen ; it is very convenient, as 
it easily dries, and becomes firm. This lute is very useful 
for joining broken china ware. 

5. For cementing stone ware to metals and wood, litharge 
and red lead mixed and worked up w T ith spirit of turpentine, 
makes a good cement. It takes several days to give off the 
turpentine and become dry and hard. 

6. Cement for fastening brass necks upon glass jars, etc. : 
— 4 parts of rosin, 1 of wax, and 1 of finely-powdered brick 
are melted and well mixed together. It is to be put on warm, 
but care is to be taken not to apply it so hot as to split the 
glass. It holds very hard. 

7. Mix linseed meal with water, and knead it into a stiff 
paste. It soon hardens, and withstands the fumes of acids 
and ammonia. It is better if made with lime water, or thin 
glue, It is charred by a strong heat. 



426 Appendix 

8. Thick gum water, with pipe clay and iron-filings. Mix 
well. It becomes very hard and firm, and is fit to be used 
where it is required to hold good a considerable time. 

9. Plaster of Paris, stirred up with milk, starch water, or 
thin glue. It hardens immediately, and is very good for 
securing tubes in flasks, when the corks do not fit well, and 
gases are to be prepared in them. 

10. Dissolve melted India rubber in boiling linseed oil 
and afterwards thicken the latter with pipe clay till it forms 
a stiff mass. The thorough incorporation of the pipe clay 
demands a great deal of labor. This is a capital cement to 
be used when acids are to be prepared. 

11. Cement for fastening Labels upon Bottles. Soften and 
subsequently boil glue in strong vinegar. During the boil- 
ing, thicken it with flour. This mixture can be preserved in 
a soft state without becoming mouldy. It should be put into 
a glass bottle, with a wide neck and a ground stopper. When 
it is to be used, it is taken out of the bottle on the point of a 
spatula, warmed over the lamp, if too thick for use, and then 
spread upon the paper. 

12. Universal Cement. Curdle skim milk, press out the 
whey, break the curd in small pieces, dry it, and grind it in a 
coffee mill. Take ten ounces of dry curd, one ounce of fresh 
burnt quick lime, and two scruples of camphor. Mix the 
ivhole intimately, and preserve it in small, wide-mouthed 
bottles, closely corked. When it is to be used, mix it with 
a little water, and apply it immediately. 

13. Diamond Cement for Glass or Porcelain. Dissolve 
five or six pieces of gum mastic, as large as peas, in the 
smallest possible quantity of alcohol. Mix this liquid with 
two ounces of a strong solution of isinglass, (made by soften- 
ing and dissolving isinglass in boiling brandy or rum to 
saturation,) having previously incorporated the two ounces 
of isinglass solution with two or three small pieces of galba- 
num or gum ammoniac, by trituration. The mixture is to be 
preserved in a well-closed bottle, and is to be gently heated 
by holding the bottle in hot water at the moment when you 
are going to use it. — Griffin's Cliem. Recreations. 



Elastic Tube Making. Take a piece of the sheet rubber, 1 orlj 
inches long, and a little more than three times as wide as you intend 
the tube to be. Take a glass rod rather smaller than the intended 



Appendix. 427 

caoutchouc tube, fold a slip of paper round the glass rod, and over it 
the piece of caoutchouc, previously softened by warming before the 
fire. Fold the two edges together, and cut off the double projecting 
edges by a pair of scissors, so as to produce two parallel straight edges. 
Put the two clean surfaces thus produced face to face, being careful not 
to let the fingers, or any thing else, touch them. Press the two faces 
together by the thumb nails, and finally press the seam from end to 
end with the flat part of the thumb nail. The junction is then effected 
and the tube complete. But if the fingers or any dirt is allowed to 
touch the clean cut surfaces of the rubber, they cannot be made to 
unite by pressure. After you have withdrawn the glass rod and the 
slip of paper from the rubber tube, you are to smear its inner surface 
with flour or fine ashes, to prevent the subsequent sticking together of 
its sides, which is otherwise liable to take place. — lb. 



Cutting Glass. Dissolve in spirits of turpentine as much camphor 
gum as tbe liquid will hold in solution by the aid of moderate heat — a 
common file dipped into the solution and applied to glass, will cut it 
with nearly the same facility as iron. 



Specific Gravity of Essential and other Oils. 

Oil of Anise-seed, 0.9958 

" " Bergamot, 0.885 

" " Cajeput, . 0.948 

" " Caraway, 0.975 

" " Cassia, . 1.071 

" " Cinnamon, 1.035 

" " Cloves, 1.061 

" " Fennel, . 0.997 

" " Juniper, 0.911 

" " Lavender, 0.898 

•« " Lemons, 0.8517 

'« " Nutmegs, 0.948 

« " Peppermint, 0.899 

" « Roses, (Ottar of Roses,) 0.832 

" " Rosemary, 0.85 

Oils of Fermented Liquors. 

Oil of Grain Spirits, 0.835 

" " Potato Spirits, . ... 821 



428 



Appendix. 



TABLE. 

The following are the results obtained by f wmmission ap* 
pointed by the Parisian Academy of Scir*.ces to examine 
the elastic force of vapor.* They we\ £ obtained by 
experiment up to a pressure of 25 atmoi,j,\eres t and at 
higher pressures by calculation. 



Elasticity of the vap. 
taking atmospheric 
press, as unity. 


Temperature ac- 
cording to Fahr. 


Elasticity of the vap. 
taking atmospheric 
press, as unity. 


Temperature ac- 
cording to Fahr. 


1 


212° 


13 


380.66° 


n 


233.96 


14 


386.94 


2 


250.52 


15 


392.86 


2J 


263.84 


16 


398.48 


3 


275.18 


17 


403.32 


3£ 


285.08 


18 


408.02 


4 


293.72 


19 


413.78 


4J 


300.28 


20 


418.43 


5 


307.5 


21 


422.9$ 


5£ 


314.24 


22 


4^7.2b 


6 


320.36 


23 


431.42 


6£ 


326.26 


24 


435.56 


7 


331.70 


25 


439.34 


?i 


336.86 


30 


457.16 


8 


341.78 


35 


472.73 


9 


350.78 


40 


486.59 


10 


358.88 


45 


491.14 


11 


366.85 


50 


510.60 


12 


374.00 







* Brande's Jour N. S. viii. 191 



GLOSSARY 



A. 

Absorption, from absorbeo, to suck up; the power or act of imbibing 

a fluid. 
Acetic Acid, from acetum, vinegar; the acidifying principle of com 

mon vinegar. 
Acicular, from acus, a needle ; having sharp points like needles. 
Action, from ayo, to move ; the effort by which one body produces, 

or endeavors to produce, motion in another. 
Adhesion, -ive, from ad, to, and hcereo, to stick; the tendency which 

dissimilar bodies have to adhere or stick together. 
Aeration, from alo, the air; the saturation of a liquid with air. 
Aeriform, from aer, the air, and forma, a form; having the forn 

of air. 
Aerostation, from al^, the air, and 'iorrju, to weigh; primarily, it 

denotes the science of weights suspended in the air; but, in the 

modern application of the term, it signifies the art of navigating 

the air. 
Affinity, from ad, to, and finis, a boundary; relationship; the force 

which causes dissimilar particles of matter to combine together, 

so as to form new matter. 
Albumen, -inous, from albumen, the white of an egg; an important 

animal principle. The white of an egg is albumen mixed with 

water. 
Alkali, a soluble body, with a hot, caustic taste, which possesses the 

power of destroying acidity; the term is derived from kali, the 

Arabic name of a plant, from the ashes of which one species is 

obtained, and the article al. 
Amalgam, from aua, together, and yaulv), to marry ; a chemical term, 

signifying the union of any metal with mercury, which is a sol- 
vent of various metals. 
Amorphous, from «,not, and uonipl, a form; not possessing regular form. 
Analysis, from ar'a, thoroughly, and kvco, to loosen; the separation of 

a whole into parts. 
Angle, from angulus, a corner; the inclination of two straight lines 

to each other, which meet together, but are not in the same 

straight line. 
Anhvdrous, from a, not, and vdwo, water; containing no water. 
Anion, from ava, up, and tlpi, to go; that which goes up; a substance 

which in electrolysis passes to the anode. 
•Anode, from ava, up, and 6Suc, a way; the way which the sun rises, 

the surface at which the electricity passes into a body, supposing 

the currents to move in the apparent direction of the "sun. 
Antiseptic, from avri, against, and a>]no), to make rotten; possessing 

the power of preventing putrefaction 



430 Glossary. 

Approximate, -ively, from ad, to, and proximus, nearest; having 

affinity with; bordering upon. 
Aqua Regia, i. e., Regal Water, a mixture of nitric and muriatic 

acids ; so called from its property of dissolving gold, held by the 

alchemists to be the king of the metals. 
Aq,ueo, from aqua, water; when prefixed tc a word, denotes that 

water enters into the composition of the substance which it 

signifies. 
Arc, from arcus, a bow; a part of a curved line, as of a circle, 

ellipse, &c. 
Armature, from armo, to arm ; a piece of soft iron applied to a load- 
stone, or connecting the poles of a horseshoe magnet. 
Astatic Needle, from aorar&g, balanced; a double magnetic needle, 

not affected by the earth's magnetism. 
Astronomy, from uotqov, a star, and vouoc, a law or rule; the science 

which treats of the heavenly bodies, their motions, periods, &c, 

and the causes on which they depend. 
Athermanous, from a, not, and StQuog, heat; that through which 

heat will not pass is said to be athermanous. 
Atmosphere, -ic, from arubc, vapor, and oyaiQa, a sphere; the sphere 

of air which surrounds the globe. 
Atom, -ic, from a, not, and rhiroj, to cut; a minute particle, not sus- 
ceptible of further division. 
Attraction, -ive, from ad, to, and traho, to draw; the tendency which 

bodies have to approach each other. 
Austral, from auster, the south; southern. 
Axis, in geometry ; the straight line in a plane figure, about which it 

revolves to produce or generate a solid; more generally, the right 

line conceived to be drawn from the vertex of a figure to the 

middle of the base. 

B. 
Barometer, -rical, from fiugog, weight, and ^trqov, a measure ; an 

instrument for measuring the varying weight of the atmosphere. 
Bibulous, from bibo, to drink; that which has the quality of drinking 

in moisture. 
Binary, from bis, twice ; containing two units. 
Boreal, from boreas, the north ; northern. 

C. 

Calorimeter, from color, heat, and metrum, a measure an instrument 

for measuring caloric. 
Capillary, from capillus, a hair; resembling or having the form 

of hairs. 
Capsule, from capsula, a little chest; a small, shallow cup. 
Carbon, from carbo, a coal; the chemical name for charcoal. 
Catalysis, from xara, thoroughly, and At'w, to loosen; an imaginary 

force, which is supposed to assist the decomposition of some bodies 

and the composition of others. 
Cathode, from xara, downward, and odbg, a way, the way which the 

sun sets ; the surface at which electricity passes out of a body, 

supposing the current to move in the apparent direction of the sun. 
Cation, from z«t«, down, and Ji/<, to go; that which goes down; a 

suDstance which in electrolysis passes to the cathode. 
Caustic, from xaiw, to burn ■ possessing the power of burning. 



Glossary. 431 

Chemistry, -ical, from an Arabic word, signifying the knowledge of 

the substance or constitution of* bodies ; the science whose object 

it is to examine the constitution of bodies. 
Circumference, -tial, from circum, around, and fero, to bear; the 

line which is the boundary of a circle. 
Cleavage, Plane of ; the plane in which crystals have a tendency to 

separate. 
Cohesion, -ive, from core, together, and hareo, to stick; the relation 

among the component parts of a body, by which they cling 

together. 
Combustion, from comburo, to burn; the disengagement of light and 

heat which accompanies chemical combination. 
Concave, from concavus, bollow ; curved inwardly, or hollow. 
Conduction, from con, together, and duco, to lead. The power of 

transmitting caloric, without change in the relative position of the 

particles of the conducting body. 
Cone, -ical, and -ic ; a solid figure, having a circular base, and its 

other extremity or vertex terminated by a point. 
Congelation, from con, together, and gelo, to freeze; the process of 

freezing. 
Congeries, from congeries, a heap; a mass of bodies heaped up 

together. 
Constituent, from constituo, to put together; that of which any thing 

consists or is made up. 
Contact, from con, together, and tango, to touch; the relative state 

of two things which touch one another, but do not cut. 
Contraction, from con, together, and traho, to draw; the state of 

being drawn into a narrow compass. 
Convergent, from con, together, and vergo, to bend; tending to one 

point from various parts. 
Convection, from con, together, and veko, to carry ; the power in fluids 

of transmitting heat or electricity by currents. 
Convex, from con, together, and veko, to qarry ; curved outwardly, or 

protuberant. 
Corpuscular, from corpus, a body ; composed of or relating to atom?. 
Coruscation, from corusco, to flash or shine; a flash, or quick vibra- 
tion of light. 
Crucible, from crux, crucis, a cross; a little pot, such as goldsmiths 

melt their gold in ; so called from having a cross impressed upon it. 
Crvophorus, from xqi'oc, cold, and q>ioa>, to produce; an instrument 

for showing the relation between evaporation at low temperatures 

and the production of cold. 
Crystalographv, from y.orara?.7.oq, a crystal, and yQcupco, to describe; 

the science which treats of crystals. 
Crystal, -line, from y.oraraXloq, ice; a substance having a regular 

form, as rock-crystal, which resembles ice. 
Crystallization; the formation of crystals during the passage of 

certain bodies from a fluid to a solid form. 
Cube, -ic ; a solid figure, contained by six equal squares. 

D. 

Decomposition; the resolution of a compound body into its compo* 

nent parts. 
Decrement, from decresco, to grow less; the quantity by which any 

thing decreases or becomes less. 



432 Glossary. 

Deflagration, from deflagro, to burn ; burning. 

Deflection, from de, from, and fiecto, to bend ; a turning aside out 
of the straight way. 

Degree, from de, down, and gradus, a step ; a quantity in measure- 
ment — as, in geometry, the 360th part of the circumference of a 
circle. 

Deliquescence, from deliqueo, to melt ; a gradual melting, caused by 
the absorption of water from the atmosphere. 

Density, from densus, thick ; vicinity or closeness of particles. 

Dephlogisticated ; deprived of phlogiston, the supposed principle 
of inflammability. 

Detonation, from detono, to thunder; explosion, accompanied with 
noise. 

Diameter, from Sta, through, and pfrQov, a measure ; the line which 
passes through the centre of a circle, or of any other curvilinear 
figure. 

Diaphanous, from Sia, through, and <pahw, to shine ; that which allows 
a passage to the rays of light. 

Diatherma#ous, from dice, through, and dlQ^og, heat; that through 
which heat will pass is said to be diathermanous. 

Dilatation, from differo, to bear apart ; the act of extending into 
greater space. 

Dimorphous, from dig, twice, and ^ioQ(pij, a form; having two forms. 

Disc, from discus, a quoit ; the apparent surface of a heavenly body. 

Disintegration, from dis, meaning separation, and integer, whole; 
an utter separation of particles. 

Dispersion, -ive, from di, in different directions, and spargo, to scat- 
ter ; the act of scattering. 

Disruption, from dis, in different directions, and rumpo, to break; 
the act of tearing asunder. 

Dissection, from disseco, to cut to pieces; the act of separating into 
pieces. 

Distillation ; separation drop by drop ; the process by which a fluid 
is separated from another substance, by first being converted into 
vapor, and afterward condensed drop by drop. 

Divellent, from divello, to tear asunder; that which causes sepa- 
ration. 

Divergent, from di, in different directions, and vergo, to bend; tend- 
ing to various parts from one point. 

Dodecahedron, from daiSexa, twelve, and sdqa, a base or side; a solid 
figure contained by twelve equal sides. 

Dynamics, -ical, from dvvapig, power; that branch of mechanical sci- 
ence which treats of moving powers, and of the action of forces 
on solid bodies, wnen the result of that action is motion. 

& 

Ebullition, from ebullio, to boil , the act of boiling. 

Efflorescence, from effloresco, to blow, as a flower ; the formation 
of small crystals on the surfaces of bodies, in consequence of the 
abstraction of moisture from them by the atmosphere. 

Elasticity, -ic, from llavvm, to push or thrust; the property bodies 
possess of resuming their original form when pressure is re- 
moved. 

Electrode, from %X$xtqov, electricity, and 68og, a way ; the point at 
which an electric current enters or quits the body through whiclt 
it passes'. 



Glossary. 433 

Electrography, from i]).ty.rnov and yqucpcj; a method of copying 
meaals, copperplate, &c, by galvanism. 

Electrolysis, -i.yte, &c, from \\Xaxrqov, electricity, and Ivw, to 
loosen ; the act of decomposing bodies by electricity. 

Electro-magnetism ; magnetism produced by electricity. 

Electrometer; an instrument for ascertaining the quality and quan- 
tity of electricity in electrified bodies. 

Electrophorus ; an instrument for producing electricity. 

Electroscope ; an instrument for exhibiting the attractive and re- 
pulsive agencies of electricity. 

Element, -aky, from elementum, an element; that which cannot be 
resolved into two or more parts, and contains but one kind of 
ponderable matter. 

Ellipse, from **, deficiently, and Asi'ttw, to leave; one of the conic 
sections, formed by the intersection of a plane and a cone, when 
the plane makes a less angle with the base than that formed by 
the base and the side of the cone. 

Empirical, from *r, in, and tcsiquoucu, to make trial; that which is 
made or is done as an experiment, independently of hypothesis or 
theory. 

Empyreumatic, from tv, in, and nvq, fire ; having the taste or smell 
of burned animal or vegetable substances. 

Endosmose, from evdov, within, and cbofibg, the act of pushing; a flow- 
ing from the outside to the inside. 

Epidermis, from LtI, upon, and dtq^ia, the skin; the exterior layer of 
the skin. 

Equilibrium, from cequus, equal, and libra, a balance ; the state of rest 
produced by forces equally balancing one another. 

Equivalent, from cequus, equal, and valeo, to be worth ; equal in 
value. 

Etiolation ; the blanching of vegetables by exclusion from light. 

Evaporation, from e, out, and vapor, vapor; the conversion of a 
liquid into vapor. 

Exosmose, from {•'£«, without, and wfr^oc, the act of pushing; a flow- 
ing from the inside to the outside. 

Expansion, from expando. to open out; the enlargement or increase 
in the bulk of bodies, which is produced by heat. 

Experience, from experior, to attempt, to try ; knowledge gained by 
observation 

Experiment; omething done in order to discover an uncertain or 
unknown eifect. 

Sxplosion, from ex, out, and plaudo, to utter a sound ; a sudden ex 
pansion of an elastic fluid, with force and a loud report. 

F. 

Ferruginous, from ferrum, iron; of iron. 

Filter ; a strainer. 

Filtration ; the process whereby liquids are strained. 

Flexure, from fleclo, to bend ; the act of bending; also, the bend or 

curve of a line or figure. 
Focus, -cal, from fo'us, a fireplace ; a point in which a number of rays 

of light or heat meet, after being refracted or reflected 
Formula ; a general theorem ; it is called algebraic, logarithmic, &c., 

according to the branch of mathematics to which it relates. 
Friction, from- frico, to rub ; the rubbing or grating of the surfaces of 
19 



434 Glossary. 

bodies upon one another ; also, the retarding force caused by thii 
rubbing of surfaces together. 

G. 

Galvanism, from Professor Galvani ; current electricity is sometimes 

so called. 
Galvanometer; an instrument for measuring galvanism. 
Gas, -eous ; a term first introduced by Van Helmont ; a permanent, 

aeriform fluid. 
Gelatinous, from gelo, to freeze ; resembling jelly. 
Goniometer, from yam'w, an angle, and ^dxqov, a measure ; an instru- 
ment for measuring angles. 
Gravitation, from gravis, heavy ; the abstract power which draws 

bodies towards each other's centres. 
Gravity, from gravis, heavy ; the natural tendency of bodies to fall 

towards a centre. 
Gravity, Specific ; the relative gravity of a body considered with 

regard to some other body, which is assumed as a standard of 

comparison. 

H. 

Halo, from odwg, a crown; a luminous circle, appearing occasionally 
around the heavenly bodies, but more especially about the sun 
and moon. 

Heliographic, from ijXioc, the sun, and yqucpw, to write; delineated 
by the sun. 

Helix, from sZtoao), to twist round ; a screw or spiral. 

Hemisphere, from ijftiovg, half, and ocpaiQcc, a sphere; the half of a 
sphere, formed by a plane passing through the centre. 

Hermetic Seal ; when the neck of a glass vessel or tube is heated 
to the melting point, and then twisted with pincers until it be 
air-tight, the vessel or tube is said to be hermetically sealed, or to 
have received the seal of Hermes, the reputed inventor of chem- 
istry. 

Heterogeneous, from %rsQog, different, and yhog, kind; different in 
nature and properties. 

Homogeneous, from bfibg, alike, and ytvog, kind; alike in nature and 
properties. 

Horizontal, from o^t'tca, to bound or terminate; parallel to the hori- 
zon. 

Hydrate, from v8u>q, water; any uncrystallized substance which con- 
tains water in a fixed, definite proportion. 

Hydro, when prefixed to the name of a chemical substance, denotes 
that hydrogen enters into the composition of the substance which 
it signifies. 

Hydrometer, from vdwQ, water, and ^lirQov, a measure ; an instru 
ment for comparing the density and gravity of liquids with water. 

Hydrostatics, from vScoq, water, and ararbg, standing ; that branch 
of natural philosophy which treats of the pressure and equilibrium 
of non-elastic fluids, and also of the weight, pressure, &c, of 
solids immersed in them. 

Hygrometer, from vygbg, moist, and uitqov, a measure ; an instru- 
ment for ascertaining accurately the quantity of moisture in the 
atmosphere. 

Hygroscope, from vyQog, moist, and axotciw, to consider ; an instru- 
ment for exhibiting aporoximatively the moisture of the atmo* 
phere. 



Glossary. . 435 

Hypo, from vnu, under ; when prefixed to a word, denotes an inferior 
quantity of some ingredient whieh enters into the composition of 
the substance which it signifies. 

Hypothesis, -tical, from imb, under, and ri^ti, to place ; a princi- 
ple supposed or taken for granted in order to prove a point in 
question. 

JU 

Impinging, from impingo, to strike against ; dashing against. 

Incandescent, from incandesco, to grow white ; white or glowing 
with heat. 

Incidence, from in, upon, and cado, to fall; the direction in which 
one body fails on or strikes another ; the angle which the moving 
body makes with the plane '"f the body struck, is called the " angle 
of incidence." 

Increment, from incresco, to increase; the quantity by which any 
thing increases or becomes greater. 

Induction, -ive, from in, to, and duco, to lead; the process of reason- 
ing, by which we are led from general to particular truths. 

Induction, Electrical ; the effect produced by the tendency of an 
insulated electrified body to excite an opposite electric state in 
neighboring bodies. 

Inductometer ; an instrument for measuring electrical induction. 

Inertia, from inertia, inactivity; the disposition of matter to remain in 
its state of rest or motion 

Inflammable, from in, and jlamma, a flame ; capable of burning with 
a flame. 

Inflection, from in, to, and flecto, to bend. 

Insulation, from insula, an island; when a body, containing a quan- 
tity of free heat, or of electricity, is surrounded by non-conductors, 
it is said to be insulated. 

Integrant, from integer, whole, entire; those parts of a body which 
are of the same nature with the whole, are called integrant. 

Interstices, from interstitium, a break or interval; the unoccupied 
spaces between the molecules of bodies. 

Iridescent, from iris, the rainbow; marked with the colors of the 
rainbow. 

Isomeric, from inog, equal, and [itnog, a part; substances which con- 
sist of the same ingredients, in the same proportion, and yet differ 
essentially in their properties, are called isomeric. 

Isomerism ; that portion of chemical science which treats of isomeric 
substances. 

J. 

Juxtaposition, from juzta, near, and pono, to place ; the placing of one 
thing close to another. 

L. 

LAMiNiE, from lamina, a thin plate ; extremely thin plates, of which 
some solid bodies are composed. 

Lens, from lens, a bean; properly a small glass in the form of a bean 
but more generally it means a piece of glass, or other transparent 
substance, having its two surfaces so formed that the rays of light, 
in passing through it, have their direction changed, and are made 
to diverge or converge, or to become parallel after diverging or 
converging. 

Levigation, from lavis, smooth ; the art of reducing to a light powder. 



436 • Glossary. 

Liquefaction, from liquefacio, to make liquid , the process of convert 

ing into a liquid state. 
Litmus ; a blue pigment obtained from the lichen rocella; it is a mo# 

delicate test of acids, which turn it red. 
Loadstone, i.e., Leadstone ; an ore of iron having magnetic properties 

M. 

Magnet, from Magnesia, a town in Asia Minor ; artificial magnets art 

small bars of steel or iron, which, when placed at liberty, turn cne 

end to the north. 
Magnetism ; the peculiar property possessed by certain ferruginoua 

bodies, whereby, under certain circumstances, they attract and re- 
pel one. another according to certain laws. 
Magneto-Electricity ; electricity produced by magnetism. 
Malleable, from malleus, a hammer ; that which is capable of being 

spread by beating. 
Maximum, from maximus, greatest; the greatest value of a variable 

quantity. 
Mechanics, from {irj%avt t , a machine; the science which treats of the 

laws of the rest and motion of bodies. 
Metallurgy, from fiha?.?.ov, a metal, and tqyov, a work ; the art of 

working metals, and separating them from their ores. 
Mineralogy ; the science which treats of bodies not being vegetable 

or animal. 
Moiree Metallique, from moir6e, a watered silk ; when tin plates are 

washed over with a weak acid, the crystalline texture of the tin 

becomes apparent, forming a crystalline appearance, which has been 

called Moiree Mctallique. 
Molecules, -ar, a diminutive from moles, a mass; the infinitely small 

material particles of which bodies are conceived to be aggregations. 
Momentum, from moveo, to move ; the product of the numbers which 

represent the quantity of matter and the velocity of a body, is 

called its momentum or quantity of motion. 
Mucilaginous ; resembling mucilage or' gum. 
Multiple, from multiplico, to render manifold ; a quantity is said to be 

a multiple of another when it contains that other quantity a certain 

number of times without a remainder. 

N. 

Nascent, from nascor, to be born ; in the moment of formation. 

.Negative, from nego, to deny ; quantities to which the sign of subtrac- 
tion, or negative sign, is prefixed, are called negative quantities; 
this sign is also used to denote operations which are the reverse 
of those denoted by the positive sign. 

Nodes, -al, from nodus, a knot; in the doctrine of curves, a node is a 
small oval figure made by the intersection of one branch of a curve 
with another. 

Normal, from norma, a rule ; according to rule. 

Nucleus, from nucleus, a kernel ; the central parts of a body, which are 
supposed to be firmer, and separated from the other parts, as th* 
kernel of a nut is from the shell ; also, the point about which mat- 
ter is collected. 

O. 

Oblate, from ob, in front of, and latus, broad ; flattened or short- 
ened. 



Glossai y. 437 

Oblong, from ob, in front of, and longus, long ; greater in length than 
in breadth. 

Octohedron, -AL,from o*Ta>, eight, and "sdga, a side; a solid figure con- 
tained by eight equal and equilateral triangles. 

Olefiant Gas from olcuvi, oil, and fio, to become ; a colorless, taste- 
less gas, which derives its name from its property of forming an 
oil-like liquid with chlorine. 

Optics, from bjtroftai, to see ; that branch of natural philosophy which 
treats of vision, and of the nature and properties of light, and of the 
various changes it undergoes. 

Organic Matter, from oQyarov, an organ ; when matter possesses or- 
gans, or organized parts for sustaining living action, as animals and 
plants, it is called organic. 

Organization ; construction in which the parts are so disposed as to 
be subservient to each other. 

Oscillation, from oscillor. to swing; the vibration or reciprocal ascent 
and descent of a pendulum. 

Oxide ; a combination with oxygen, not being acid. 

Oxidizable ; capable of being converted into an oxide. 

Oxygen, from ozvg, acid, and ytvvaxo, to produce ; a colorless, aeriform 
fluid, which was formerly supposed to be the universal acidifying 
principle. 

P. 

Parabola, from Tiaqa, parallel to, and /?d^o>,to place ; one of the conic 
sections, formed by the intersection of a plane and a cone, when the 
plane passes parallel to the side of the cone. 

Parallel ; a term applied in geometry to lines and planes, which are 
every where equidistant from one another; straight lines, which, if 
infinitely produced, never meet, are called parallel straight lines. 

Parallelogram : a four-sided figure, of which the opposite sides are 
parallel and equal. 

Parallelopipedon ; a solid figure contained by six parallelograms, 
the opposite sides of which are equal and parallel. 

Pellicle, a diminutive from pellis, a skin or crust ; a thin crust formed 
on the surface of a solution by evaporization. 

Pendulum, from pendeo, to hang; a heavy body so suspended that it 
may vibrate, or swing backward and forward about some fixed 
point, by the action of gravity. 

Percolate, from per, through, and colo, to strain ; to strain through. 

Permeate, from permeo, to pass through; to penetrate. 

Perpendicular; the straight line which, standing upon another 
straight line, makes the adjacent angles equal, and consequently 
right angles, is said to be perpendicular to the line upon which it 
stands. 

Phenomenon, from (paivo.uai, to appear; an appearance. 

Philosophy, -ical, from cpiXfo, to love, and oocpia, wisdom ; the study 
or knowledge of nature or morality, founded on reason and expe- 
rience, the word originally implying " a love of wisdom." 

Phlogiston, from <px*'yc», to burn ; a name given by the older chemists 
to an imaginary substance, which was considered as the principle 
of inflammability. 

Phosgene, from ip&g, light, and yswda>, to produce ; produced by light. 

Phosphorus, from ipwg, light, and <p'oto, to produce; a highly inflam- 
mable substance, obtained from calcined bones, which emits light 
when placed in the dark. 



438 Glossary. 

Photometer, from (prog, light, and pj-TQov, a measure ; an instrument 
for measuring the different intensities of light. 

Physiology, -ical, from qwdig, nature, and Kyog, an account ; the 
science which treats of the structure of living beings. 

Pneumatics, from nvsv^a, air; that branch of natural philosophy 
which treats of the weight, pressure, and elasticity of aeriform fluids 

Polarity; the opposition of two equal forces in bodies, similar to that 
which confers the tendency of magnetized bodies to point to the 
magnetic poles. 

Polarization ; the communication of the above opposition of forces. 

Polarized Light; light which, by reflection or refraction at a certain 
angle, or by refraction in certain crystals, has acquired the prop- 
erty of exhibiting opposite effects in planes at right angles to each 
other, is said to be polarized. 

Poles of a Magnet ; points in a magnet where the intensity of the 
magnetic force is a maximum ; one of these attracts, and another 
repels, the same pole of another magnet. 

Pores, from noQog, a passage ; the small interstices between the solid 
particles of bodies. 

Precipitation, from prcecipito, to fall suddenly; the separation of a 
solid from a liquid; a triangular glass solid used for the separation 
of rays of light by refraction. 

Projectile, from pro, forward, and jacio, to throw; a heavy body pro- 
jected, or cast forward into space, by any external force. 

Proportion ; the relation of equality subsisting between two ratios. 

Pyrometer, from uvq, fire, and ^utqov, a measure ; an instrument for 
measuring higher degrees of temperature than can be ascertained 
by a thermometer. 

Pvroxylic Spirit, from tivq, fire, and oSi)c, acid ; a colorless, transpa- 
rent spirit, obtained by the destructive distillation of wood. 

Pyro ; when prefixed to a word, denotes that the substance which it 
signifies has been formed at a high temperature. 

Photography, from (pvjg, light, and yqaipw, to write ; writing with the 
sun's rays. 

a 

Quadrant ; the fourth part of the circumference of a circle. 

R. 

Radiation, from radius, a ray; the shooting forth in all directions 

from a centre. 
Radical, from radix, a root; the original principle of a compound. 
Radius ; the straight line drawn from the centre to the circumference 

of a circle. 
Rarefaction, from rarus, rare, and facio, to make ; the act of causing 

a substance to become less dense ; it also denominates the state of 

this lessened density. 
Ratio ; the relation which subsists between two quantities of the same 

kind, the comparison being made by considering what multiple 

part or parts one of them is of the other. 
Ray ; a beam of light propagated from a radiant point. 
Reaction ; the reciprocation of any impulse, or force impressed, made 

by the bod y en which such impression is made. Reaction is alwayg 

equal to action. 
Rectangjle, from rectus, right, and angulus, an angle ; a four-sided plane 



Glossary. 439 

figure, in which all the angles are right angles, 'and its opposite 

s^des equal and parallel. 
Rectification; the process of drawing any thing off by distillation, in 

order to make it more pure and refined. 
Rectilinear ; consisting of, or bounded by, straight lines. 
Reflection, from re, back, and Jiecto, to bend ; the act of bending back ; 

when rays of light fall on the surfaces of bodies, part of them are 

thrown back or reflected. 
Refraction, from re, back, a.ndfra,7igo, to break ; the deviation of rays 

of light from their direct course, when passing through media of 

different densities. 
Refrangible; susceptible of refraction. 

Refrigeration, from re, again, zridfrigo, to cool; the act of cooling. 
Repulsion, from re, back, and pello, to drive ; that property in certain 

bodies whereby they mutually tend to recede and fly off from each. 

other. 
Retort, from re, back, and torqueo, to twist ; a vessel with a bent neck, 

which is made use of in chemical operations. 
Rhombus ; a figure which has all its sides equal, but its angles are not 

right angles. 
Rhombohedron; a solid figure, whose sides are composed of rhombs. 
Rhomboid ; a figure which has its opposite sides equal, but all its angles 

are not equal, neither are all its angles right angles. 

s. 

Salifiable Bases, from sal, salt, and fio, to become; bodies capable 
of combining with acids to form salts. 

Saturation, -ated, from satur, full ; the solution of one body in an- 
other until the receiving body can contain no more. 

Scale, from scala, a ladder ; an instrument in which a line is divided 
into small and equal parts, and which is applied for the purpose of 
ascertaining the relative dimensions of other lengths not so divided. 

Section, from seco, to cut ; a cutting, or part separated from the whole. 

Segment of a Circle ; any portion cut off by a straight line. 

Sine; the straight line drawn from one extremity of an arc, perpen- 
dicular to the radius which passes through the other extremity. 

Solution, from solvo, to loosen ; in chemical language, any fluid that con- 
tains another substance dissolved in and intimately mixed with it 

Solvent; any substance which will dissolve another. 

Specific, from species, a particular sort or kind ; that which denomi- 
nates any property which is not general, but is confined to an in- 
dividual or species. 

Spectrum ; the colored image formed on a white surface by rays of 
light passing through a hole, and being refracted by a glass prism. 

Sphere ; the solid figure formed by the rotation of a semicircle about 
its diameter. 

Spheroid, -al ; a solid figure, formed by the revolution of an ellipse 
about one of its axes ; hence it is sometimes called an ellipsoid ; 
the spheroid will be oblate or prolate, according as the revolution 
is performed about the minor or major axis of the ellipse. 

Statics, -ical, from ararbc, standing; that branch of mechanical 
science which treats of the equilibrium, pressure, weight, &c., of 
solid bodies when at rest. 

Stratum, from sterno, to strew ; a layer. 

Symmetry, -ical, from avv, together, and fiirQov, a measure; confor- 
mity of measure. 



440 Glossary. 

Synthesis, from avv, together, and ri9tjui, to place; the composition 
of a whole from its parts ; in mathematics, the process of reasoning 
out new principles from those already established. 

Sublimation, from sublimis,' high ; the act of raising into vapor bj 
means of heat, and condensing in the upper part of a vessel. 

Synchronous, from ovv, together, and xquvogj time ; performed in tha 
same time. 

T. 

Tactile, from tango, to touch ; of or relating to touch. 

Tangent, -ial ; the line which touches a circle or any other curve, but 
does not cut it. 

Ternary, from ter, thrice ; containing three units. 

Tetrahedron, from rtocaqt-s, four, and a'd^a, a base or side ; a solid 
figure contained by four equal and equilateral triangles. 

Theory, -etical, from Sscoqicc, a view; a collected view of all tha» 
is known on any subject into one. 

Thermo-Electricity ; electricity produced by heat. 

Thermometer, from -d-tguog, heat, and yJ.TQov, a measure; an instru- 
ment for measuring the degrees of heat. 

Thermoscope, from -d-tQiiog, heat, and axonico, to view ; an instrument 
for exhibiting the powers of heat. 

Tire ; a hoop of iron used to bend and receive the felly of a wheel. 

Torsion, Force of, from torqueo, to twist; a term applied by Cou- 
lomb to denote the effort made by a thread which has been twisted 
to untwist itself. 

Transparent; a term to denote the quality of a substance which not 
only admits the passage of light, but also of the vision of external 
objects. 

Triturated, from trituro, to thrash ; reduced to powder. 

Truncation, from truncus, cut short ; the cutting off a portion ot a 
solid, as of the solid angle of a crystal., 

TJ. 

Undulation, from unda, a wave ; a formation of waves. 
Uniaxal, from unus, one, and axi3, an axis; having but one axis 

V. 
Vacuum, Latin ; a space empty and devoid of all matter. 
Ventilation, from ventus, wind; the supply of fresh air. 
Vernier; an instrument invented by Vernier; it consists of a small, 

movable scale, running parallel to the fixed scale of a quadrant o? 

other instrument, and having the effect of subdividing the divisions 

of the instrument into more minute parts. 
Vibration, from vibro, to brandish ; the regular reciprocating motion 

of a body, as of a pendulum, &c; a motion to and fro. 
Volume, from volumen, a roll ; the apparent space occupied by a body 

w. 

Weight ; the pressure which a body exerts vertically downward in 
consequence of the action of gravity. 

Z. 
SJero; the numeral 0, which fills the blank between the ascending 
and descending numbers in a series. 






INDEX. 



icttate of -alumina 359 

ammonia 358 

copper 359 

iron 360 

lead 358 

zinc 360 

potassa 358 

methyle.. . .? 364 

Acetic ether 355 

Acetone 360 

Acetous fermentation 350 

Acid, acetic 357 

aconitic 380 

aldehydic 357 

amygdalic 369 

antimonic 274 

antimonious „ 274 

apocrenic 383 

arsenic . 267 

arsenious 265 

benzoic 367 

boracic 216 

bromic 153 

capric 390 

caproic 390 

carbazotic 395 

carbonic .... 184 

cerebric 406 

cholic 403 

cholinic 403 

chloric 147 

chloranilic 395 

chlorous 147 

chloriodic 151 

chlorocarbonic 1 89 

chromic 269 

cinnaminic 371 

citric 380 

cocinic 389 

columbic 273 

comenic 383 

srenic 383 

croconic 382 



Page. 

Acid, cyanic 1 96, 373 

cyanuric 196, 374 

elaidic 389 

ellagic 383 

fellinic 403 

fluosilicic 221 

fluoboric 217 

formic 364 

fulminic 196, 373 

gallic 382 

humic 346 

hydriodic 164 

hydrobromic. 4 165 

hydrochloric 1 62 

hydrocyanic 137, 374 

hydroferrocyanic 376 

hydrofluoric 165 

hydromellonic 377 

hydrosalicylic 370 

hydroselenic 219 

hydrosulphocyanic 375 

hydrosulphuric 205 

hydrosulphurous 206 

hydrotelluric 178 

hydrothionic 107 

hypochlorous 146 

hyponitrous 173 

hypophosphorous 210 

hyposulphuric 202 

hyposulphurous 200 

hypuric 369 

indigotic 395 

iodic 151 

isatinic 395 

kakodylic 361 

kinic 382 

lactic 382 

lithic , 378 

malic 380 

margaric 388 

manganic 250 

meconic 383 

mellitic 382 



442 



INDEX. 



Page. 

Acid, metagallic. 383 

molybdic 272 

moroxylic 383 

mucic 348 

muriatic 182 

nitric 174 

nitre-hydrochloric 1 76 

nitrohydrorluoric 177 

nitrous 173 

nitromuriatic 176 

oleic 383, 389 

oleophosphoric 406 

osmic. 272 

oxalic 371 

palmitic 389 

paracyanuric 197 

paraphosphorie 212 

perchloric 148 

permanganic 250 

periodic 151 

phosphoric 212 

phosphovinic 356 

Acidulous springs 416 

Acid, phosphorous. 211 

prussic 197, 374 

pyrogallic 383 

pyroligneous 358 

pyromucic 348 

pyrophosphoric 212 

racemic 381 

sacharic 348 

salecylic 370 

sebacic 389 

selenic 219 

selenious 218 

silicic 220 

silicohydrofluoric 221 

stearic 388 

succinic. 383 

sulpindigotic 396 

sulphoglyceric 388 

sulphomethylic 364 

sulphovinic 356 

sulphuric 202 

sulphurous 200 

tannic 381 

tartaric 380 

tartralic 381 

tartrelic 381 

telluric 278 

tellurous 278 

titanic 277 

tungstic 272 

uric 378 



Page. 

Acid, valerianic 366 

vanadic 271 

Affinity, chemical 113 

disposing 15£ 

double 114 

effects of. 120 

elective 113 

measure of 119 

simple 114 

Air 168 

Alabaster 304 

Albumen 398 

Alcohol 351 

Aldehyde 357 

Alkalies, metallic bases of 228 

Alkaline earths 237 

Alkarsine 360 

Alkargene T 361 

Allontoin 378 

Alloys of antimony 278 

copper 280 

lead 282 

manganese 251 

silver * .. 28^ 

sodium and potassium . . . 235 

Alloxan 379 

Alloxantin 379 

Alizarin 396 

Alum 308 

ammonia 308 

Alum stone 308 

iron 308 

manganese 309 

Alkaline springs 416 

Alumina 244 

Aluminium 244 

Aluminous earth 244 

Amalgams 285 

Amaryth.ru. 396 

Amber 392 

Ambergris 39 1 

Ammeline 378 

Ammelide . , 378 

Ammidogen 17? 

Ammonia 178 

Ammonium 179 

Amygdaline 369 

Amylic alcohol 365 

Analysis of carbonate of hme. 414 

Analysis of minerals 413 

mixed gases 4 12 

Analysis of mineral waters. . . 41G 

organic compounds 331 

Anhydrite 304 



INDEX. 



443 



Page. 

Anthracite 181 

Animal heat 401 

Antunonio-sulphurets 333 

Antimony 273 

Aqua ibriis 174 

Archil 306 

Aerostation 157 

Arrow-root 313 

Arseniates 319 

table of compounds 320 

Arsenic 264 

Arsenites 320 

Arsenio-sulphurets 332 

Atomic theory 126 

Auro-chlorides 333 



Balloons 157 

Balsam of sulphur 391 

Balsam 392 

Barium 237 

Barometer 53 

Baryta 237 

Bell-metal 280 

Benzamide 368 

Benzile » 368 

Benzoic ether 356 

Benzole 368 

Benzoinc 368 

Benzoyle 366 

Biborute of soda 322 

Bicarbonate of ammonia 324 

notassa 323 

soda 323 

Bicarburet of nitrogen.. . 196, 372 

Bichromate of potassa 321 

Bichloride of cyanogen 197 

molybdenum 272 

platinum 291 

tin 260 

titanium 2" ^ 

tungsten o*.^ 

395 

•'•• 403 

... 403 

...' 403 



Page. 

Binoxide of molybdenum 271 

nitrogen „. . 172 

platinum 291 

tungsten 272 

tin 260 

vanadium 271 

Bisilicates 326 

Bismuth 276 

Bisulphuret of carbon 207 

calcium 242 

cobalt 263 

iron 254 

mercury 285 

potassium 232 

platinum 292 

tin.. 261 

selenium..... 219 

titanium 278 

Bisulphate of potassa. 303 

soda 303 

Bitartrate of potassa 380 

Bituminous coal 181 

Black dyes 397 

lead 181 

oxide of copper 280 

oxide of iron 253 

Bleaching 144 

powder 242 

Block tin 259 

Blood 399 

Blue vitriol 307 

dyes 394 

Bone phosphate of lime 318 

Bones 405 

Boracic ether 355 

Borates t . . . 321 

Borax , 322 

Boron 215 



Bro 



406 
280 
151 
316 



Bichlorisatine 

Bile.... 

Cileverdin 

Bilin 

Biniodide of 

tin platinum .... 

Binox : 

,de of barium 

columbium 

copper. , 

gold 

hydrogen £± 

mercury 



260 
238 
273 
280 
287 
161 



brass ..,...., r • • 

Bromine 

Bromates 

Bromide of carbon ^ 

Bromide of amyl.e gob 

bismuth £{{ 

calcium *** 

barium £>» 

cyanogen ™' 

iodine J&J 

lead..-; *g 

magnesium **J 

sodium *g 

sulphur £"£ 

phosphorus •-• »**■ 



444 



[NfiXX, 



Fags. 

Bromide of potassium 231 

selenium 219 

silicon 221 

zinc 257 

Bromoform. 365 

Brucia 386 

Butter 390 

Butyrine. « 390 

O. 

Cadmium 257 

Calatilic force 336 

Calcium 240 

Caloric . 25 

absorption of 32 

conduction of . . 26 

effects of 36 

radiation of 29 

reflection of 31 

theories ....■ 32 

Calomel 284 

Camphene 192 

Camphor 392 

Canton's phosphorus 241 

Calorimotor 81 

Caoutchouc 393 

Carbon 180 

Carbonates 322 

ammonia 323 

baryta 324 

lead 325 

lime 324 

magnesia 324 

potasssa 322 

orotoxide of iron 325 

soda 323 

strontia 324 

Carbonic oxide 184 

ether 344 

Carbosulphurets 331 

ammonia 332 

barium 332 

calcium 332 

sulphuret of lithium 332 

magnesium 332 

potassium 331 

sodium 332 

Carburet of manganese 251 

iron 255 

Carmine 396 

Caramel 347 

Caseine 398 

Cast iron 255 

steel.....' .... ....... 255 



Cassava . 343 

Cementing , 425 

Cerium 276 

Chalybeate springs 416 

Cholisterin "403 

Charcoal 181 

Chloral 189 

Chloranile 395 

Chlorates 313 

baryta 314 

potassa 31 3 

Chloride of barium 238 

amyle 365 

benzoyle 367 

bismuth 277 

bromine 153 

cadmium 258 

calcium 241 

carbon 291 

cobalt 262 

copper 280 

cyanogen 197 

kakodyie 361 

lead 282 

lime 242 

lithium 236 

magnesium 243 

methyle 362 

nikel 264 

potassium 231 

salicyle 379 

selenium 219 

silicon 221 

silver 287 

soda 235 

sodium 234 

strontium 239 

tellurium 278 

zinc 257 

Chlorisatine 295 

Chloroform 365 

Choke-damp 187 

Chlorine 141 

Chlorites 315 

Chromates 321 

lead 321 

potassa 321 

oxide of zinc 321 

Chromium 268 

Chyle 403 

Cinchonia 385 

Citrine 192 

Cleavage 295 

faces of 292 



1NDKX, 



U5 



Page. 

Cleavage, direction of 296 

Coal gas 193 

Cobalt 261 

Cochineal 396 

Cocoanut oil 389 

Codeia 386 

Cohesion 115 

Coloring matters 394 

Columbium 273. 

Combustion 142 

Composition of blood 401 

Compound blowpipe 160 

Compound radicals 299 

Conia 386 

Copal 392 

Copperas . 294 

Copper 279 

Copper pyrites 280 

Corrosive sublimate 284 

Cream of tartar 327 

Creosote 393 

Croton oil 389 

Crucibles 199 

Crystal 293 

Crystallization 293 

Crystalography 293 

Cyanogen 196, 372 

Cyan ate of ammonia 373 

Cyanide of lead 282 

barium 239 

kakodyle 361 

manganese , 251 

methyle 363 

nickel 264 

silver 287 

sodium 235 

zinc 257 

potassium 233, 375 

Cupellation 286 

Cuticle 406 

Cystic oxide 405 

D 

Daguerreotype 69 

Decrepitation ... 297 

Definite proportions 122 

Deflagration 105 

Deflagrator 82 

Deliquesce 297 

Diamond » 180 

Dichloride of copper 280 

mercury 284 

Dicarbonate of mercury 326 

Dicarburet of hydrogen 190 



Page, 

Dicyanide of mercury 285 

Digester, Marcet's 55 

Diphosphate of potassa 316 

ammonia 318 

lime..,. 318 

magnesia 318 

Diphosphuret of iron 255 

Dinitrate of protoxide of lead. 311 

Diniodide of copper 280 

Dioxide of copper 279 

mercury 283 

Disulphate of piotoxide of cop- 
per 307 

Disulphuret of iron 254 

nickel 264 

Dodecahedron 296 

Dolomite 326 

Double bromides 334 

cyanides 335 

fluorides 335 

iodides 320 

Ductility 223 

E 

Ebullition 52 

Efflorescence 297 

Eggs 405 

Elasticity 109, 117 

Electricity 73 

Electrical machine 74, 75 

Electro-chemical decomposi- 
tion 91 

Electrodes 89 

Electrography 112 

Electrometer, gold leaf 75 

balance 78 

Electro-magnetism 94 

theory 105 

Electro-magnetic multiplier. . . 95 

telegraph 109 

Electrophorus 78 

Electrotype 104, 1 12 

Emetia 386 

Emulsion 387 

Eremacausis 346 

Erythrilin 396 

Erythrin 396 

Essences 391 

Etching 166 

Etherine 192, 357 

Etherole 357 

Ethiop's mineral 255 

Ethyle 352 

Eudiometer... ... .. 160 



446 



INDEX: 



Page. 

Eupione 192 

Evaporation 59 

Exhilirating gas 171 

F 

Feathers . 40G 

Fermentation of sugar 349 

Ferro-cy anide of potassium . . . 376 

iron 376 

Ferrid-cyanogen 377 

Fibrine 397 

Filtration 418 

Fire damp 194 

Fixed oils 387 

Flowers of zinc 306 

Fluoride of barium 238 

calcium 241 

lead 281 

lithium 236 

magnesium . . . 243 

methyle •.-. 363 

potassium 231 

sodium 235 

strontium 240 

zinc 257 

Fluorine 153 

Food of plants 408 

Formate of ammonia 364 

baryta , 364 

copper , 365 

lime . . .. * • . 365 

magnesia , 365 

mercury 365 

potassa 364 

silver 365 

strontia , „ . . . 365 

Formic ether 355 

Fowler's arsenical solution . . . 320 

Freezing mixtures 50 

Fulminating gold 289 

platinum 292 

silver 287, 374 

Fusion 110 

Fusion, watery 297 

G 

Galena 281 

Galvanism 79 

theories 85 

effects of. 87 

Gasometers 137 

Gaslights 192 

Gastric juice 403 

Gaseous mixtures 412 



Page- 
Gaseous mixtures containing 

carbonic acid 413 

hydrygen 413 

nitrogen 413 

oxygen 413 

Gelatine 398 

sugar 399 

Germination 407 

Glass 221 

green bottle 221 

crown 221 

plate 221 

flint 221 

Glauber's salts 309 

Glucina 246 

Glucinium 246 

Glue 399 

Gluten 344 

Glycerine 387 

Glycocoll 399 

Gold 288 

powder 290 

Green vitriol 305 

Graphite 255 

Gum 344 

arabic 344 

Senegal 344 

tragacanth 345 

resins 393 

Gun cotton 345 

Gypsum 304 

H 

Hair 406 

Hartshorn 323 

Heavy oil of wine 356 

Hematoxylin 397 

Hematine 399 

'Hexahedron 294 

Homberg's pyrophorus 308 

Hog's lard 350, 390 

Honey 349 

Hoofs 406 

Horn 406 

Humus 346 

Hydriodate of ammonia 328 

Hydriodic ether 353 

Hydro-salts 328 

Hydrobromic ether 353 

Hydrochlorate of ammonia . . 328 

Hydrochloric ether 352 

Hydrobromate of ammonia. . . 329 

Hydrofluate of ammonia 329 

Hydrocyanate of ammonia . .. 329 



i^m.x. 



44? 



Page. 

Hydrogen 154 

Hydrargochlorides 333 

Hvdrosulphocyanides 331 

Hyduret of arsenic 268 

potassium 232 

Hygrometers G2 

Hyponitrous ether 354 

I 

Idoform 365 

Idrialine 192 

Ignition 71 

Indefinite proportions 122 

Indelible ink 313 

India rubber 393 

Indigo 395 

Induction „ 76 

Ink .... 382 

Insolubility 1 16 

Iodates 315 

Iodate of potassa 315 

Iodide of barium 238 

calcium 241 

cadmium 258 

kakodyle 361 

lead 282 

magnesium 243 

methyle 363 

silver 287 

sodium 235 

phosphorus 213 

sulphur 205 

potassium 231 

Btrontium 240 

zinc 257 

locfine 148 

lion 251 

Iron pyrites 244 

Iridium 292 

Isatine 395 

Ising-glass 399 

Isomerism 127 

Isomorphism 297 

Ivory-black 181 

K 

Kakodyle 360 

Kalium 228 

Kermes mineral 275 

L 

t.efces 394 

Lactine 348 

Lamp-black 181 



Page. 

Lapis causticus 230 

Latanium 293 

Lead 281 

Legumine 398 

Leyden jar 77 

Light 67 

reflection of 67 

refraction of 67 

decomposition of 68 

absorption of 70 

carbureted hydrogen. . . . 190 

Liquefaction 49 

Lignin 345 

Lime 240 

Lime-water 240 

Liquorice 349 

Litharge 281 

Lithia 236 

Lithium £ 236 

Litmus 306 

Loaf-sugar 347 

Lucifer matches 314 

Lunar caustic 312 

Lymph 404 

M 

Madder 396 

Magnesium 242 

Magisetry of bismuth 277 

Magnesia 243 

Magnetic iron pyrites 254 

Magic circle 99 

Malleability 222 

Magneto-electric induction . . . 105 

Magneto-electric machine 1 05 

Manganese 248 

Manna 349 

Margarine 388 

Matches 310 

Membranes 406 

Metals 224 

Metallic lustre 224 

Metaphosphates 319 

Mercury 283 

Mellone 377 

Mellonide of potassium 379 

Melome 377 

Melomine 377 

Mercapton 354 

Milk 404 

Microcosmic salt 317 

Mineral green 352 

Molasses 347 

Molybdosulphureta , . 332 



448 



INDEX 



Page. 

Molybdosulphuret of potassa. . 332 

Molybdenum 271 

Morphia 384 

Mosaic gold 261 

Mucic ether 349 

Mucus 404 

Murexide 379 

Murexan 379 

Muscle ,',... 406 

N 

Nails 406 

Naphtha 192 

Naphthaline 192 

Narcotina 385 

Natron 233 

Nickel 263 

Nicotina 386 

Nitre v 310 

Nitric ether 354 

Nituret of potassium 232 

Nitrates 309 

Nitrate of ammonia 310 

baryta 310 

lime 311 

magnesia 311 

methyle 363 

potassa 309 

soda 310 

strontia 311 

}>rotoxide of copper 311 

ead 311 

mercury 311 

oxide silver 311 

Nitrites 313 

Nitrogen < 166 

Notation 134 

Nomenclature 130 

Nourishment of animals. 410 

Nux vomica 386 

O 

Oblique prisms 295 

rhombic prisms 295 

rectangular 295 

rhomboidal 295 

Octohedron 295 

Octahedron, regular 295 

square 295 

rectangular 296 

rhombic 296 

GEnanthic ether 356 

Oils 387 

Oil of bitter almonds 366 



Oil of cinnamon 371 

Oleine 389 

Olefiant gas 19(! 

Olive oil . . ., 389 

Orcein 396 

Orpiment 268 

Osmium 292 

Oxalate of potassa 372 

of lime 372 

methyle 363 

Oxalic ether 355 

Oxalyle 371 

Oxigenation 141 

Oxidation 141 

Oxide of selenium 218 

cadmium 258 

carbon 184 

methyle 362 

phosphorus 210 

titanium 277 

silver 287 

strontium 240 

Oxychlorides 334 

chromium 270 

copper . 334 

iron 334 

lead 334 

Oxygen 136 

Oxysalts 301 

Oxysulphuret of antimony . . . 275 

P 

Palladium 292 

Palladio-chlorides 333 

Palm-oil 389 

Paranapthaline 192 

ParrafHne 192 

Parmelia 396 

Parilla 386 

Peat 181 

Pearlash 323 

Perbromide of phosphorus 213 

Percussion powder 314 

Perchlorates 315 

Perchloride of iron 253 

manganese 250 

phosphorus 21 3 

Periodide of arsenic 268 

iron 254 

carbon 189 

Perfluoride of iron 254 

manganese 251 

Perphosphuret of hydrogen... 229 

Peroxide of strontium.. ... .... 239 



INDEX, 



449 



Page. 

Peroxide of calcium « 241 

manganese 249 

iron 253 

cobalt 262 

four-three oxcobalt 2G2 

titanium 277 

tellurium 278 

lead 282 

Permuriate of tin 260 

Persulphuret of arsenic 268 

tellurium 278 

Perphosphuret of iron 255 

Pewter 275 

Phloridzine. . . , 370 

Phosphureted hydrogen.. 213, 229 

Phosphorus 208 

Phosphorescence 71 

Phosphates 316 

Phosphate of potassa 316 

soda and ammonia 317 

ammonia 318 

lime 318 

magnesia and ammonia. . 318 

"".osphuret of potassium 232 

cadmium 259 

calcium 242 

manganese 251 

barium 239 

%ch 392 

aehbeck 280 

rnotometers 72 

,'hotographic drawing 69 

platinum 291 

spongy 291 

Platinochlorides. 333 

Plumbago 181 

Pneumatic cistern 137 

Pot-metal 281 

Portable gas 193 

Potassa 230 

hydrate 231 

Potassa- fusa 23 1 

Potassium 228 

Potassamide 340 

Potash and pearlash 323 

Potato oil 365 

Printers' types 275 

Proteine . ; .• 398 

Protobromide of iron 254 

potassium 23 1 

protochloride of iron 253 

tin 260 

carbon 188 

manganese 250 



I'age. 
Protochloride of arsenic ...... 267 

cerium 276 

mercury 284 

gold 290 

platinum 291 

uranium 276 

Protocyanide of iron 255 

Protiodide of iron 253 

cadmium 258 

carbon 189 

tin 260 

platinum 292 

Protohyduret of arsenic 268 

Protophosphuret of chromium. 270 

strontium . . 239 

Protosulphuret of arsenic 268 

platinum 292 

mercury 285 

cerium •. . . 276 

cobalt 263 

nickel 264 

manganese 251 

tin 261 

iron 254 

strontium 240 

calcium 241 

potassium 232 

Protosulphocy anide of iron . . . 255 

Protoxide of strontium 239 

cerium 276 

hydrogen 158 

bismuth 277 

nitrogen 171 

potassium 230 

gold 289 

sodium 234 

copper 280 

lithium 236 

barium 237 

lead 281 

calcium 240 

magnesium 243 

mercury . . 284 

thorium 247 

manganese 248 

iron 252 

platinum 291 

zinc 257 

tin 259 

cobalt 263 

nickel 263 

vanadium 271 

molybdenum 271 

uranium 275 



450 



INDEX. 



Page. 

Prussian blue 376 

Pus 404 

Putrefactive fermentation 346 

Pyracetic spirit 300 

Pyrometers 46 

of Wedge wood 46 

of Daniel 46 

of Brequet 46 

Pyrotechny 310 

Pyrophosphates 31 8 

of soda 319 

Pyroxylic spirit 362 

a 

Quadrisilicates 327 

Q,uadrochloride of nitrogen . . . 177 

Q-uartation 288 

Quinia 385 

R 

Realgar 268 

Red dyes 396 

Red oxide of manganese 249 

lead 282 

Red precipitate 284 

Regular hexagonal prism 295 

Respiration 188 

Resins 392 

Revolving rectangle 97 

Right prisms 294 

Right square prisms 294 

rectangular 294 

rhombic 294 

rhomboidal 294 

Rhodium 292 

Rhodio-chlorides 334 

Rhombohedron 295 

Rochelle salt 338 

Rock candy 347 

salt 234 

S 

Saccnarine fermentation 349 

Safety lamp 1 95 

Sago 343 

Sal-ammoniac 328 

Saliva 403 

Salifiable base 293 

Salicine 369 

Saline springs 416 

Saltpetre 310 

Salts or ternary compounds. . 293 

Sandarac 264 

Sanguinaria 386 



Page. 

Saxon blue 396 

Scheele's green 320 

Sealing-wax 392 

Seleniurel of ammonia 245 

phosphorus 220 

potassium 232 

Selenium 217 

Sesquiphosphuret of aluminium 245 

cobalt 263 

Sesquibromide of arsenic 268 

carbonate of ammonia. . . 324 

carbonate of soda 323 

Sesquichloride of aluminium.. 245 

antimony 274 

arsenic 267 

cerium 276 

chromium 270 

uranium 276 

Scsquifluoride of chromium. . . 270 

Sesquioxide of aluminium 244 

antimony 274 

bismuth 277 

cerium 276 

chromium 269 

glucinium 246 

mangpnese 249 

nickel £64 

plati? cm 291 

sodium 234 

tin..... 260 

uranium 276 

zirconium 247 

Sesquisulphuret of aluminium 245 

antimony 275 

arsenic 268 

chromium 270 

tin 261 

cobalt 963 

Sesquisulphocyanide of iron.. 255 
Sulphocyanide of barium .... 239 

iron 255 

potassium 233, 375 

Shells 405 

Silver 236 

Silver glance 287 

Silex 222 

Silicon 220 

Silicates 326 

Silicic ethers 355 

Silicium 220 

Silica 220 

Silk...... 406 

Simple silicates 326 

Skin 40g 



INDEX. 



451 



Page. 

Solution 116 

Spirits of turpen .ne 391 

Soaps . 390 

Sodium 233 

'Soda 234 

Solder 282 

Specific gravity 129 

of essential and other oils 427 

Spongy platinum 291 

Spermaceti oil 389 

Starch 342 

Steam 56 

artillery 59 

engine 58 

generator 58 

Stearine 388 

Steel . 255 

Stream tin 259 

Strontia 239 

Strontium 239 

Strychnia 386 

Sugar 346 

of grapes 347 

of lead 358 

Subphosphuret of cobalt 263 

nickel.... : 264 

Subsesquiphosphuret of cop- 
per 280 

Sublimation 198 

Suet 390 

Sulphur 198 

flowers of 198 

rool-brimstone 198 

Sulphates 302 

Sulphate of ammonia 303 

alumina 303 

baryta 304 

lime 304 

lithia 303 

magnesia 305 

methyle 3(53 

potassa 302 

soda 303 

strontia 304 

potassa and alumina 308 

potassa and magnesia 308 

protoxide of copper 307 

cobalt T 306 

iron 305 

copper 307 

manganese 305 

mercury 307 

nickel 306 

silver 307 



Pagi. 

Sulphate of zinc , . 306 

Sulphamylic acid 3(56 

Sulphocyanide of potassium. . 375 

Sulphureted springs 417 

Sulphuret of barium 238 

boron 217 

bismuth 277 

cadmium 258 

cobalt 263 

copper 280 

cyanogen 210 

ethyle 

kakodyle 361 

lead 282 

methyle 363 

potassium 232 

silicon 221 

sodium 235 

silver 287 

uranium 276 

zinc 257 

Sulphur-salts 330 

Sulphuric ether 352 

Sweat 404 

Synaptose 369 

Sympathetic ink 262 

T 

Table of discovery of metals . . 227 

Tannin 381 

Tapioca 343 

Tar 392 

Tartar emetic 381 

Tartrate of antimony 381 

potassa 381 

soda 381 

Taurin 403 

Tears 404 

Teeth 405 

Tellurium 278 

Tendons 406 

Terchloride of boron 21 7 

molybdenum 272 

gold 290 

chromium 270 

Terfiuoride of chromium 270 

Teroxide of potassium 231 

Teriodide of nitrogen 577 

Tefphosphuret of tin 261 

Tersulphate of alumina 301 

sesquioxide of chromium. 306 

Tests of metallic ores 415 

Teroxide of gold 289 

potassium 231 



452 



INDEX, 



Page. 

Tersulphuret of tin 261 

Tertrasulphuret of iron 254 

Theory of animal heat 

constitution of salts 299 

compound radicals 346 

fermentation 351 

substitutions 341 

Thermo-electricity 108 

Thermometers 42 

air 42 

differential 43 

mercurial . . 44 

graduating of 44 

register 45 

Thorina 247 

Thorium 247 

Tin 249 

Tin foil 259 

Tincal 322 

Titanium 277 

Torpedoes . 287 

Train oil 389 

Triacic acid 

Triphosphate of potassa 316 

soda 317 

soda and basic water 317 

acid triphosphate 317 

lime 318 

magnesia 318 

ox. silver 318 

Triphosphuret of copper 280 

Trisilicates 327 

Trona 323 

Tungsten 272 

Tungstosulphurets 333 

Turkey red 397 

Turpentine 392 

Turpeth mineral 307 

U 

Universal cement 426 

Uranium 275 

Urine 404 

Urea 373 

Urinary calculi 405 

V 
Vanadium 270 



Tag*, 
Vaporization 52 

Variegated copper pyrites 254 

Varvicite 250 

Vegetable alkalies 384 

Verdigris 359 

Verditer '. 325 

Vermilion 285 

Vinegar, distilled 358 

Vinous fermentation 349 

Viscous fermentation 350 

Voltaic electricity 79 

circles 79 

pile 79 

Volta-electric induction 101 

Volatile 52 

oils 391 

W 

Water 158 

of crystallization 297 

of nitre 167 

Water gilding 290 

Wax 391, 393 

White oxide of arsenic 

White vitriol 306 

lead 

Wollaston's scale of chemical 

equivalents 420 

Wood spirit 362 

Wool 406 

Woulfe's apparatus 1 63 

X 

Xanthic oxide 405 

Xyloridine 345 

Y 

Yellow dyes 397 

Yttria 246 

Yttrium 246 

Z 

Zaffre 262 

Zinc. 256 

Zinc blende 257 

Zinetum 256 

Zirconia , 247 

Zirconium * . . 24* 



INDEX OF FIGURES 



Tig. Page. 

1. Conductometer 27 

2. Apparatus for heating liquids.. • 28 
3,4. " for conduc'n of liquids 29 
5. • " for radiation of cal .. 30 
6 " for rejection of caloric 31 

7. Concave mirrors 31 

8. Pyrometers 37 

9. 10. A pp. for expansion of liquids 38 

11. App. for expansion of air 38 

12. Air thermometer 42 

13. Differential thermometer 43 

14. Common and laboratory do 44 

15. Blowpipes 44 

16. Different scales of thermometers 45 

17. Register thermometer 45 

It'. Metallic thermometer 40 

19. Influence of [pressure on the boil- 

ing point 53 

20. Pulse glass 53 

21. App. culinary paradox 54 

22. Marcel's digester 5.5 

23. Spirit lamp 55 

24. Steam engine illustrated 58 

25. 20. Distillation. Cryophorus 59, 60 

27. Hydrometer 62 

28. App. for refraction of light 68 

29. Prism 08 

30. Gold leaf electrometer 7.3 

31. Electrical machine 76 

3-. Apparatus for induction 77 

33. Electrophoru =s 78 

£4. Balance electrometer 78 

'.'■'■>. Simple voltaic circles 80 

M >. Caliromotor 81 

37. Voltaic pile 82 

38. Deftagrator 82 

30. Grove's battery 83 

40. Smee's battery 8.5 

41. App. for decomposition of water 89 

42. Transfer of chemical substances 90 

43. App. for change of colors 90 

44. Galvanometer 95 

45. Revolving rectangle 96 

45. Hrlix and stand 98 

47. Magnet with three poles 98 

16. Electro-magnet 98 

49. Magic circle 99 

50. Vibrating magic circle 99 

51. Page's revolving magnet 1U0 

52. 53. Separable helices 102, 103 

51. Secondary currents 103 

55. Magneto-electric machine 105 

56. Theory of electro-magnetism. . . 107 

57. Elect. o-magnetic telegraph 109 

58. Electrotype 112 

59. Dropping tube 120 

60. App. for change of form 121 

61. Ills, of atomic theory 126 



Fig. 
62. 
63. 
64. 
65. 
66. 
67- 
70. 

71. 

72. 
73. 

74, 



r ,8. 
79. 
80. 
81. 

m. 

83. 

84. 

So. 

86. 

87. 

83. 

89. 

90. 

91. 

92. 

93. 

94. 

95. 

96. 

97. 

98. 

99. 
100. 
101, 
102. 

103. 
104. 
105. 

106. 
107. 
108. 
109. 
110. 
111. 
1 1 2. 
113. 
114. 
1 15, 
117. 
118. 



PujT> 

Specific gravity 123 

Aerometer 138 

Pneumatic cistern 137 

Retorts 138 

Lead tubes for connection 139 

-69. App. for oxygen 140 

App. for collection of gases 

heavier than the air 147 

App. decomposition of water .. 154 

Gas bag and bubble pipe 156 

Method of filling gas bags . 156 

75. Balloon. App. musical 

sounds 157 

H ydrogen pistol 157 

Eudiometer 160 

Compound blowpipe 161 

Woulfe's apparatus 163 

App. for nitrogen 167 

" analysis of the air ... 170 

" for nitric acid 171 

" for showing properties of 

nitric acid 175 

" for gases lighter than air. . 178 

" carbonic acid 186 

Gauze wire for flame 195 

Safety lamp 105 

Platinum wire for wicks 195 

Crystallization of sulphur 109 

Crucibles 200 

Sulphur in volcanoes 207 

Phosphorus in oxygen gas 207 

Phosphuret of hydrogen 214 

Evaporating dishes 216 

Hexahedron 294 

Right square prism 294 

'' rectangular prism 294 

" rhombic prism 294 

Hexagonal prism 295 

Rbombohedron 295 

Oblique rhombic prism 295 

" rectangular prism 295 

" rhoniboidal prism 295 

Regular octohedron 295 

Square " 295 

Rectangular " 296 

Rhombic " 296 

" dodecahedron 296 

Combustion tube 337 

Organic analysis 338 

Analysis ofliquids 339 

gases 412 

" minerals 414 

" mineral waters 417 

Test tubes 417 

1 16. Making filters 418 

Filtration 419 

Supports 419 



NEWMAN k TOMS PUBLICATIONS. 



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